Your change would be nice even with the warning I'm proposing, considering that it helps with trimming the environment block. I don't understand why it should still not import the environment block at all.
I'll reiterate why I think conditionally not importing it is a bad idea: - If modern Windows allows unlimited environment block size, Wine should allow it too - It's a change that breaks configurations for little gain - Because it's conditional, documentation becomes much more cumbersome. Think of all the resources online saying something like "set this environment variable", which will now need to be updated with "unless your environment block is too big, you'll also have to trim the environment block too" (which is more complicated than this sentence). And that's assuming it gets updated at all. Add in users why follow guides and then don't notice the log (either because they don't use the terminal or because they are newbies and can't see that this log is related to why the guide is not working), and you get a mess.