@k.kaneko I apologize for the delay in responding I didn't see your question come in. I did some research and the documentation you referenced is stale and needs to be updated. The true limitations are:
- 4 unique display devices (not visual screens, but physical displays).
- 8192x8192 max x,y resolution for each physical display.
- 8 total Themes.
- 128 total languages.
- 10K strings (for each language, it is maintained as a languages*strings table)
There is no internal limit on the number of widgets or number of resources a project may contain. I have created a task to update this portion of the documentation. Let me know if you have any other specific questions.