For the main part it seems that it has been acceptable simply to proclaim the full humanity and divinity of Christ without sin and that He really suffered and died and much else than that has been more theologoumenon rather than dogma or doctrine.
Whilst that may be the case in regard to the EOC, it is certainly not the case with regard to the OOC given the conciliar treatment of the issue and the fact men were ex-communicated in consideration of the issue. Julianism, insofar as the OOC is concerned, is nothing short of heresy.
It appears that while such is ascribed to him the true difference between Julian and Severus is that while Severus would have advocated a corruptibility by necessity Julian would have advocated a voluntary corruptibility since a necessary corruptibility would mean that Christ Himself would be in need of salvation.
This is simply not the case at all.
According to St. Severus, the Lord Christ, in His Humanity, was ontologically susceptible to all experiences proper to true Humanity; but this says nothing with respect to whether He was thus necessarily or voluntarily subject to those experiences. The latter question concerns the manner in which He underwent those experiences to which He was--in His Humanity--ontologically susceptible, and not whether He was in fact ontologically susceptible to them in the first place (which is the issue of contention between St. Severus and Julian). That St. Severus inherited St. Cyril's stress on the Word's ultimate authority over His Human experiences is clearly indicated in many of his writings. For example, in his Letter to Ecumenius, St. Severus states: “God the Word did not permit his flesh in all things to undergo the passions proper to it”.
Here, St. Severus admits that there were things proper to the Humanity the Lord Christ assumed which He nevertheless had the power to exercise discretionary governance upon—He had the volitional capacity to undergo that to which He was--in His Humanity--ontologically susceptible to, and He had the volitional capacity to conversely not
undergo such experiences. Later on in the same letter, St. Severus explains that the Lord Christ’s ability to experience Humanity in a manner far different from the way we mere human beings experience the same nature shared by the Lord Christ, is due to the Hypostatic Union: “For in many instances [His Flesh] is seen not to have undergone the things which manifestly belong to its nature; for it was united to the Word, the Maker of nature.”
Likewise, you will find statements to the converse effect i.e. that just as the Lord Christ did not undergo certain human experiences by virtue of His not permitting it, so too did He undergo certain human experiences by virtue of His consciously permitting it to be, and not because He was of necessity subject to His own Humanity.
According to Julian, on the other hand, the Lord Christ underwent true human experience contrary to His Human Nature; it’s not that He permitted His flesh to undergo that which is proper to it as far as He willed, but rather that He permitted His flesh to undergo that which was improper to it as far as He willed (and it was improper to it, precisely because, as far as Julian was concerned, the Lord Christ's Humanity was incorruptible and hence not ontologically susceptible to suffering, death etc.). That’s the key difference, and it is quite a significant difference at that.
As I argued earlier, the main reason that Julian sought to avoid attributing a fallen Humanity to the Lord Christ was due to his false anthropological premises regarding the relationship between sin and human nature.