In Roblox Studio selecting certain kinds of objects can cause extreme lag depending on the amount of selection boxes that need to be created and rendered to display “the selection”. By far the worst offender for this is Folders.
As a developer it becomes increasingly hard to use Folders and similar objects to organize my games when selecting larger folders can cause studio to freeze up for multiple seconds before responding.
Seen above is an example of the awful freeze ups in action. The Chunking folder contains hundreds of thousands of parts, models, folders, meshes, and a number of scripts. In the video I am clicking at a constant rate between multiple folders and the will always freeze up studio until selection objects can be created. Selection objects are not visible when selecting objects outside of the Workspace (everything is in ReplicatedStorage in the video) but for some reason are still created every time a new selection is made.
This can also be observed by clicking on the Workspace service. If your Workspace is populated with a lot of objects (many hundreds of thousands) it will have a similar effect.
I have a fairly competent computer (32gb of ram, i7-10700k, gtx 1070) and this is consitently a pain point for me when working on my projects in studio. Folders are great organization instances that do their job perfectly until you start to reach higher numbers of instances within them, especially so when those instances can be used as an adornee for selection boxes.
If Roblox were to address this issue it would greatly benefit the studio user experience when working on big games. Even something as crude as a studio setting to turn off selection highlighting for folders would greatly help with this pain point.