Ok I expanded that mesh re-use video to include the whole model so you can see how much you can get away with on this approach. Depending on the details you're going for, you could go even further than this.

These areas dont get mirrored because they have asymmetrical details. Theyre also large flat areas where most of the focus will be so any mirrored details will become much more obvious

I realise I forgot to mirror a couple pieces, whoopsie

This is pretty much what we have to do when making items on Roblox for their catalog but with strict limitations on size, VERTEX (not poly) and textures. In 2020-22, we had a VERTEX limit of 1400, texture limit of 256^2, polygon limit was 4k but no one ever got more then 1500 before hitting the VERTEX limit. 2022 it was changed to 4000 verts and 512 textures 2023 it was changed 512 textures for all accessories and up to 1024 textures WITH per support on specific items (i.e., bodies or body suits) ...mirroring meshed and have to reuse the same texture area for details was standard practice for our group Foxtrot Arms. We've collectively made over 3,000 items since 2020 across 3 groups. We made things work with the limits we had. If you're creative you can get a lot done with very little.. that and if your specific art style that you're going for allows you to cut corners. I.e. normal maps aren't important or textures aren't very busy. Camouflage rarely looks good mirrored:/

From experience, I know just how limiting and tricky it can be working within the specs of Roblox 😅 These weren’t for the catalogue, but tie-in events and still had their own challenges to remain as efficient as possible in-game

How do you do that scale to mirror thing? Is it a script or did you manually type in -1? It's awesome, would love to know.

I have scale snapping enabled, so it scales to whole values. Typing the value into properties works fine too

Great example of optimal modeling and texturing. These kinds of optimizations are things that keep me up at night, I don't want to waste resources and I am paralyzed by the thought I might.

Shoulda used mirror modifier. 😂

Aw dang ya got me

i really wanna see how the texture map looks

Lucky you, I got the textures on the Artstation page