I’m in this boat too, although I don’t use VIM. On macOS where mnemonic key shortcuts are the norm, function key usage is low enough that them being layered isn’t an issue, and layered arrows are actually nice than dedicated once you’re used to them.

I have a few boards with the HHKB layout, only a couple of which are HHKBs. For me the layout is nearly perfect, just wish I could have it in my laptops too.