At any rate, I think he has the best take I have encountered in the scholarship re: Gregory's use of dia tou yiou, and I reproduce a brief excerpt from one of his works here with the hope that it will entice people interested in this subject to read the entire work. I've transliterated Greek text in what I hope to be an understandable way; footnote citations are omitted, and bolding is mine.
The conclusion is that one cannot understand the significance of the dia tou yiou
if one does not pay attention to the personal characteristic of the Spirit: the one who united the Father and Son and who leads to unity. For, with a beautiful expression of B. Forte, the Spirit is the "us in person of the divine communion." Thus, one can affirm that, in the context of Nyssian thought, the Spirit as syndetikon is the exegesis of the dia tou yiou, from which it can never be separated. This should be the most original contribution of the present study: this connection is almost totally passed over in the literature, which is principally dedicated to the study of the divinity of the third Person and, in the few cases in which his procession is treated, one gets often sidetracked in polemics of verbal Byzantinism.
Thus it was seen, that the base of the whole Nyssian construction is the continuity between economy and immanence: the sending of the Holy Spirit by the Son cannot be solely limited to the economic sphere.
It is probable that this development of Gregory's Trinitarian doctrine is due to the great value that he places in creation and to the purification of the remnants of Origenistic intellectualism that still slowed down Basil's pneumatology. For the Spirit is, at the same time, the One who brings to completion the dynamic of intra-Trinitarian union and who attracts and unites man and the world to the Triune God, inserting them in his vortex of life and love.
The summit of Gregory's pneumatology is then, precisely the recognition of the personal characteristic of the Third Person: he who leads to union, in immanence as in the economy. He is the syndetikon, the bond. His mode of being God, his mode of containing the unique divine essence, is the holos einai: that is, to carry to unity, to constitute a whole. This syn- of syndetikon recalls immediately the syn- in the syneklamponta of the Son with the Father: in this way it is shown that the fundamental category is intra-Trinitarian koinonia. B. Forte cites 2 Cor. 13.13 and auspiciously notes that, precisely due to his personal characteristic, in the greeting use by the primitive Church koinonia was attributed to the Holy Spirit.
In this sense, the accent moves to the Trinity as union of love. In the communion of the Father and the Son, which point one to the other, on the real level as on the logical level, the Spirit is not a complement, a simple extension toward the economy, fruit of an almost subordinating conjoined spiration. The Spirit rather unites the Father and the Son in as much as Spirit of the Father and of the Son.
Trinity and Man: Gregory of Nyssa's Ad Ablabium (Supplements to Vigiliae Christianae series, vol. 86, Brill: Leiden and Boston, 2007), p. 184-85.
Fr. Maspero goes on to make the explicit connection to Latin theology on pp. 185-87:
So, in the Nyssian dia tou yiou the accent is placed on the tou yiou, on the communion of the Father and the Son, and not on the pure passivity of the dia. The same phenomena will be reproduced in Latin theology, where the nexus amoris eliminates the danger of dialectically and logistically opposing the Son to the Father, in generation as well as in spiration. The nexus amoris shows, in fact, that in the Filioque the accent is on the Filio and not on the que. With the same operation the dangers of "theological filioqueism" are eliminated, which, with an almost rationalistic coldness, dissects the Trinity, separating Paternity and Filiation from Spiration and Procession.In my opinion, Fr. Maspero closes some important gaps in the pioneering work of Fr. David Balas, and Fr. Maspero does a great deal to correct the misinterpretations of Latin theology and Gregory's work as a result of the "verbal Byzantinism" described above. Upon reading his work, one will not doubt that he supports his position with close textual analysis, and I must again commend the study of this excellent work for those who wish to grasp the complicated issue of the Spirit's procession from the Son.
Such a deformation would lead to negate the Trinitarian reciprocity of the Spirit in relation to the Father and the Son. In fact, from a purely logical viewpoint, only the Father and the Son are in relative opposition. The temptation is then born to move from the logical level to the real one, affirming that, while the Spirit is relative to the Father and the Son, united in the unique spiration, one cannot say however that the Father and the Son are, in their turn, relative to the Spirit.
In synthesis, in Latin terms, l'unus Spirator is unus precisely by the Person of the Spirit, who is the union, the syndetikon, of the duo spirantes, united and distinct in their proper Paternity and Filiation by their mutual Spirit. Spiratio is, in fact, the unique respiration of love of the Father and Son: to be Son does not only mean to receive all from the Father -- to be his perfect Image but also to give to the Father perfect glory, to give everything back to the Father. It is in this manner that the Son manifests the Spirit in his Filiation to the Father, who is in this way fully Father, receiving his own glory from his own Son. This is the circular dynamic of glory seen in the [Adversus Macedonianos, De Spiritu Sancto]. But, at the same time, since it is proper of the Son to give to the Father all glory, it is the Son who sends the Spirit in the economy, extending into time the eternal movement that characterizes him as Person, to attract all to the Father. The Spirit is then like the eternal 'regard' of the Son to the Father, which for love of the Father himself reposes on creation and is extended as the gaze of the Crucified Christ, that fascinates and conquers. Gregory's equilibrium is, thus, perfect.
Therefore, while confronting Nyssian pneumatology with Latin doctrine, two considerations are necessary: on one side Gregory purifies the category of 'cause' of the temporal dimension and of substantial inferiority, transforming it into a notion that signifies fundamentally 'origin'. Thus the Nyssian aitia is notably closer to the Latin principium. On the other hand, it is also necessary to consider that Occidental pneumatology does not intend, with the Filioque, to introduce a second cause in the Trinity. The key point is the consideration of the Spirit as bond of union in the Blessed Trinity.