I concur with this feeling, and ended up deciding to create a Visual Studio Code extension that works in a similar fashion: code editing on one tab, auto running the ROM on another. It's heavily inspired by 8bitworkshop, but adds all the goodies a good editor allows you like having other include files, code navigation, shortcuts, being offline, etc. A truly modern, no-compromise approach to 6502/Atari development, in my opinion.
The caveat is that I just started it and it's nowhere near ready. Right now it only allows editing asm files with some language features. It does dasm compilation on the background (for error checking etc), but doesn't export ROMs nor does it open the emulator tab with the ROM yet. I've been adding features at a constant pace though - just added navigate-to-definition yesterday, for example - and hope to have exporting/emulating soon. Also, it's open source, so anyone can contribute with suggestions/bug fixes/features/etc.
(I swear I didn't join the forum just to spam this - I've been lurking for a while - but thought it was worth mentioning now.)