When I read this, I think of the shell's "readline", and that are using in app links.
What precisely is the issue if I may ask? What are the 'app links' ?
As for the broken busybox 1.36.1 shell (the double prompt bug),
In cases where users can not remaster the iso (for what-ever reason, such as their vps host only allowing official distribution media, or simply because they find it complicated enough already to just dd the iso onto their usbstick), I see no way how to replace it and work around the issue.
By the time we get our first and seemingly only chance to slip something in (the httplist boot parameter), busybox shell is already in use.
IF there is no way to fix it, that it is to late to change the official iso, I fear those users will have to resort to an additional separate static busybox-ash that is not version 1.36.1 for their prompt (though a bunch of native tools and scripts are set to 'busybox ash' and thus wouldn't trigger their separate standalone busybox ash, I think. I'm just trying to think of solutions here... (in case it is to late to fix the release/iso)).
Edit: Or learn to wait a good second before typing your next command (in case your current prompt just suddenly ends (holding the first part of what you typed) and new prompt appears).