Glad I could help ;) Although for me, setting the IPD to a lower value than default 64 did the trick, setting it higher increased the zoomed-in effect, so yeah maybe it is a vision thing. However, as Ralf said, setting the FOV to 120 or the highest possible value is essential and you have to make sure it is effectively set at 90 or 120 because, as in your Arma 3 case, it may only appear that it is set to 120, but when checking on 2D display it turns out to be the default low FOV.
Regardless how u apply instructions from the Essential Game Hints combined with the IPD setting, a vorpx supported game will always look fine in the end, even better than native ones in some cases, as long as you can manually increase the FOV. But for some games, where FOV can’t be changed or increased to much like BF Hardline, the zoomed in problem can only be diminished using Ralf’s Essential Game Hints, but it’s still there. So that’s why successfully setting the correct FOV value is so important.