For polycount, we recommend keeping your Space below 100k if you want it to work on Mobile or standalone VR (such as the Quest). There are many ways to optimise your space by balancing polycount, materials, textures, etc. so if your space runs well on the Playground (and tested on low end systems) it is acceptable to mint. It is not recommended to test on a high end system and assume it will work well on a low end system however. We are looking at ways to help with this process.