First off, comparing screens with the Vive Pro (or regular Vive) doesn't really apply, mainly due to single vs dual diplay config.
I do like the idea of a thinner gasket, but again, I think the solution is going to have to be focussed on 1) a better software based lens correction system, then 2) use a different gasket to get a bit closer. Losing a bit of FOV is going to have to be the tradeoff, but it's one that has to be made when dealing with 6DoF world-scale style tracking.
To give you an idea, I demoed our latest app to others, and ALL said that they felt dizzy or slightly off. What we made used an in-engine light source off the player camera to try and soften the effect of the warping (almost like a vignetting effect), it ran at a solid 75fps and was run in a solid tracking area (about 120m² walkable space). In other words, it was the best we were able to do.
HTC, please give us the option to choose between the agressive lens correction aimed at higher FoV you have now, and something less agressive (even if there is a lower FoV).