I just turned 60 and it seems like a switch flipped and my eyes cant see the d@%m front sight. My wife got me a Romeo 3Max red dot sight and I need to find a good and visible co-witness solution. I'm having a hard time locating suppressor height co-witness sights for this configuration. If anyone has a source for Sig co-witness sights, I would appreciate the tip. Because of my optical challenges I was also wondering if there is a fiber optic (or other highly visible) co-witness solution.

I would give Dawson Precision a call. They are very knowledgeable sight people. They even made an extra tall front for me, once.
https://dawsonprecision.com/

I checked with Dawson and they suggested I reach out to Sig Sauer. I am awaiting their reply. After doing some additional research online (https://optics-info.com/footprints-on-red-dot-sights/), I found that the Romeo 3Max red dot is built to the “C-More Standard” mounting platform standards. From there, I was able to identify a C-More to P220 mount at EGW Guns (https://www.egwguns.com/vortex-razor-sig-sauer-p220-p226-p229-p320-sight-mount-fits-c-more-sts-sts2-rts2).

I also found that I can ship my slide to Patriot Defense (patriotdefense.com) where they will mill it to fit the Romeo 3Max and send it back in a couple weeks.

I used dawson front sight that I bought at galloway precision for $41.00 site says 7 in stock