I assume you did not see my posts on this topic. In the first I explain why the distance between lenses (centers) is bigger than the IPD value the headset shows (Some thoughts on the IPD discrepancy) and in the second I explain how the perspective projection (angular verity) is screwed up when you set the lenses closer than they should be (Clarifying Near IPD x Distant IPD confusion).
What you advertise here and on the reddit as a method for setting up an IPD is a myth perpetuated on this forum all the time = that in order to have an IPD set correctly, one must see a clear image in both eyes (when focusing on the same distant virtual spot). My second post above explains why it cannot work this way.
On top of that, using the fixed image, (which is rendered this way Pimax native projection and pre-lens warp transformation) introduces another false indication as it seems to project the image at the plane which is at infinity.
While there are people who seem to prefer to sacrify the angular verity in favor of a clear image (as you do), such setting can lead to other issues (as severe as the ones related to blurry images) and I would definitely not promote it as a solution to the problem, without giving the explanations of the consequences I made above and a big disclaimer.
Here are my two recent posts, why I believe that the IPD setting is a tricky subject, which does not have easy and reproducible solution. ([Pimax Response Required] Is there an official solution for eyestrain and IPD issues in the works?), (Eyestrain discussion / Problems and Solutions).