Yes, you can with Blender. Shuajota did a full edit for Euroleague arenas on 2K19, structure is mostly the same so it should work in the same way. I remove slip mat for arenas on 2K20 and it works too.
Can you edit crowd positions too? I mean, can you do it all in one model at Blender? I don't have NBA 2K20, but I'm using Blender to edit stadiums, just wanted to ask.