Incorrect. It does increase compilation time, which is why for heavy packages it’s not enough to comment a function call, you also need to comment the package import for some extra performance boost. I noticed it a lot with a few packages that were used in the paper (like grayness and pintorita imports alone add 4 s). But visually it does nothing, and for the vast majority of simple non-Wasm(?) packages the added package code evaluation adds negligible amount of time to the compilation process.
They would, but maybe they wouldn’t. Must specify concrete use case. For performance, you’ll have to profile the project.