I think this matter is VERY important because the solution to the issue also improves the PIMAX 4K:
The original face pad has a thickness of almost 1 cm.
While using this original padding the VR experience to me always seemed a bit "tunneled" like looking at the world through toilet paper tubes.
When after one year the original padding gave up on me I ordered a set of VIVE replacement pads on Amazon.
But I did not buy the thick ones, I got the thinner ones only being about 6mm thick.
There was a HUGE imrovement in the field of view!
No more "tunneled" vision and also the image sharpness improved for me because of less blur.
I strongly would advise ALL Pimax 4k USERS to replace their thick pads with thinner ones!
The only disadvantge would be for people that need to wear glasses - the thinner padding does not allow wearing glasses while using the Pimax 4k