We're on SP2019 and wondering how we might go about creating a custom "form" for a document library. If we were on SP Online then I know PowerApps would be the answer here, but is SPFx the way forward for this? And if so, does it work the same way as creating a custom property pane for a webpart? The two seem similar, but I don't quite understand how I'd customise the details pane.
The problem we're trying to solve, is that our business will have LOTS of content types (for better or worse). So we'd like to produce a "cascading dropdown" to group these content types to make selection of the correct content type easier for the user.
We do have Nintex Forms, but I find the Nintex forms experience jarring in modern libraries. I'm certain our users will be keener on editing a documents properties in the Details Pane, rather than having to open the item menu > More > Properties then wait for the form to load, then have to put the form into Edit mode, fill it in, and then save it.
Compared to the property pane, I think that's pretty horrific.
Thoughts and suggestions welcome please and TIA