> And the new framework is so niche it's now hard to hire for it.

Why do you need to specifically "hire for a framework"? Wouldn't any front-end developer be able to pick up any front-end framework (unless it's outside the javascript space entirely, and requires knowledge of purescript, rescript, elm, rust, clojure, scala, etc.)

I don't want to dox myself by getting too specific, but yes it's essentially a frontend framework for backend engineers in a niche lang (at least, niche for frontend). So they'd just hire more backend engineers in their language of choice.

I think this might actually be fine for internal tooling, but this is a customer-facing web app. It's now incredibly clunky and every feature takes an age to get out. Full page reloads for everything, etc.