By just observing the increase in the time it takes to publish a place in Roblox with many linked sources, I am getting the feeling that all the individual linked source files are being published as individual HTTP requests one at a time sequentially. This is now taking pretty long time for a project with many linked sources now.
Whether this observation is true or not under the hood, the linear increase in time per linked source file added seems unacceptable. It would be nice to have this process more optimized somehow to reduce the marginal increase in time per linked source added in the future.