Multiselect over a range of 200 arbitrary values isn't something that will ever be solved by a single control, so that's a complete straw man.
If you actually need to multi-select over 200 arbitrary values (you almost certainly don't), the best way to do it I've seen is a way to filter the displayed items, a "Select All" button for what's visible based on that filter, and maintaining the "checked" state through filter changes, allowing you to select anything matching multiple filters.
this problem was solved around 1986 by Norton Commander and one of the main reasons why two-panel file managers (FAR, mc, TotalCommander) are still in use.
When you decouple selection with cursor and make selection "permanent", so you can move around this list without fear to lose accumulated selection, you could pick needed elements one-by-one, sort list by any attributes to simplify selection, apply filters, etc.
Yep. When marking many files for selection the twin-pane file managers let your mind (and your stomach) rest easy. I sometimes use ranger with two or more tabs to similar effect.
There was/is a Tcl/TK twin-pane file manager I liked called FileRunner. It's showing it's age now and needs a rewrite -- not for beauty, which I'm not too concerned about, but for some glitches that have crept in with time and lack of maintenance. It seemed more mouse friendly than some other twin-pane FMs (or maybe it's just rose-tinted memory).
I'm using FAR in Windows (10 now) every day. I'm using it as my command-lime shell, really, never run cmd or powershell. For everything my console needs (and I'm using a lot of coretools/filetools in the form of mingw64).
I don't know how to live on Windows without it, it is first program I install, even earlier than alternative browser.
Usually with 200 or so values there is some categorization of values that exists - maybe it's counties in a state that can be divided into regions or songs by an artist that can be divided into album or period. Large multi-selects seem to necessitate a multi-step selection process where the user can drill down (All of this category, none of this one and some of this other one - specifically this, this, not this and that). I think it's feasible for such a tag proposal to make its way through various working groups but it'd be pretty opinionated and we'd likely end up dividing multi-select inputs into several different classes (which would probably be a good thing).
If you actually need to multi-select over 200 arbitrary values (you almost certainly don't), the best way to do it I've seen is a way to filter the displayed items, a "Select All" button for what's visible based on that filter, and maintaining the "checked" state through filter changes, allowing you to select anything matching multiple filters.