... Y'all ...
Wanting keyboard navigation is not an unreasonable ask. Saying "Just get a mouse" is a really dismissive "solution" - and "Learn git, C#, and unity and then digest the ins and outs of the codebase, just so you can have keyboard navigation" is even moreso. Some folks don't like mice, and for some it's even impractical - to say nothing of the actual accessibility concerns.
Using arrow keys for keyboard navigation is *probably* fairly low-impact, doesn't interfere with any existing functionality, and makes for a better user experience for some.
Okay, sure, it's probably not a huge segment of the playerbase, but despite that, to say "No. Deal with it." to a reasonable request *when you aren't even the developer* is a really crappy thing to do.
Heck, I *am* a mouse user, and I would love to have keyboard navigation that would effectively pan by a screen's worth of distance, too.