KEYB.COM / CHCP.COM - keyboard combination to switch codepages, synchronize layout with host

[Torinde]

1. When using a non-Latin script codepage (e.g. Cyrillic) the box drawing characters of most installers and programs are missing/rearranged (because they're hardcoded for 437).

It would be great if KEYB or Staging itself supports a key-combination to change between 437 and whatever codepage is active - for example 3021 moves around the box drawing characters and back in the day we used TSR programs allowing LeftShift + RightShift to change between the codepages on-the-fly (when you need to see something like a game installer menu, which is written in 437, but soon after you'll change back to 3021 in order to read/write in Cyrillic). I mentioned it before here.

2. Alt+Shift (current way to change scripts)- either sync with host (changing on host changes also in Staging, changing in Staging changes also on host) or decouple fully from host (changes on host never affect Staging, changes in Staging never affect host). Currently if I press in Staging Alt+RightShift that changes to Cyrillic both in Staging and on host (coincidence, because both Staging KEYB and Windows use the same key combo to switch?) - nice, so I can type with the same alphabet in both, but then while I'm on the host and I switch back to Latin (Alt+RightShift - Windows uses the same combo to revert - unlike KEYB which needs Alt+LeftShift) Staging doesn't follow and in general it becomes annoying if you go between host/Staging and type in both - soon they get out of sync with each other and you think/expect your layout is Latin, but it's not, etc.

I don't see an obvious "best" solution here, so just sharing to see what you think and most importantly is that something you want to improve.

Same topic: #3128 (comment), joncampbell123/dosbox-x/issues/3634. #3523 (comment), Related #3233, #3498 (comment)

To illustrate why LeftShift+RightShift combo is needed for user to switch to/from 437 - see how EDIT looks with 3021:

While how it should look:

[NicknineTheEagle]

When using a non-Latin script codepage (e.g. Cyrillic) the box drawing characters of most installers and programs are missing/rearranged (because they're hardcoded for 437).

CP 866 actually keeps all the pseudographic characters (unlike CP 855 which is why it never took off in Russia).
But I know that some European code pages replace them (e.g. CP 850).