Issue
Selecting, expanding, or searching Explorer becomes slow in a large place.
Cause
Very large instance trees, plugin listeners, and expanded hierarchies increase editor work.
Fix
Update Studio to receive current Explorer performance work, disable suspect plugins, collapse large generated trees, and keep runtime-only objects out of the edit-time hierarchy where practical. Use tags and focused searches instead of expanding the entire DataModel.
Verify
Profile the same place with plugins disabled and compare selection and search responsiveness after updating Studio.
Official Roblox Studio performance update
#1
Original Heliotrope guidance with authoritative Roblox sources.