Capturing conditionally required Opportunity Custom Fields

We are working toward getting our public grants team fully integrated with NXT. As this tool wasn't really made for public grants, there are a good deal of custom-field-workarounds happening.

I don't want to be overly involved in the day-to-day data entry for this group--the work lives outside the fundraising office--and I have doubts about just giving a group of custom fields to include on all public grants. I imagine this will turn into a data hygiene challenge if it is not somehow directed in a ‘wizard’ sort of way. So I'm wondering if it makes sense to have some sort of automation through Power Apps, Power Automate, or MS Forms. I figured my first stop should be here, to see if anyone else has already tackled a problem like this? My brainstormed solutions are looking a little convoluted.