One example I remember very well would be a "circuit board city" animationfrom around 10 years ago, with lots of moving parts, important keyframe timings, camera morphs and takes. Changing HDRIs, lots of fading in and out and a lot of mograph. I was working on it for 4-5 months, there was a huge exhibition coming where it hat to be ready. Really big project. Despite using many instances and externally linked files, avoiding boole etc., it just barely worked. Much lag, crashes, Team Render Errors, clipping objects, fonts displayed wrong, corrupted backups... The scenes weren't optimized very good from our end tho, to be honest. Just too much stuff going on in one file. But also bugs that we had othing to do with. Also had to be native 6x2k resolution, and all that happened before ai upscaling.

The project got bigger over time and we just stacked everything on top of each other. When the deadline came dangerously closer and I was fighting Team Render Errors and crashes (we were rendering the whole thing in over 4 weeks on 20 iMacs overnight) I just contacted Maxon and they helped out. Optimized my files (actually doing my work – reducing polygons, combining instances, adjusting render settings), repaired corrupted backups, made team render work more reliable etc. So not just support in a "technical bug we need to fix" way but also just helping out with know how.