Thank you for volunteering to work on wider improvements!
I suggest that you start by ensuring that all the existing reports
provide machine readable output (for example json). Then you could work
on new, better UX based reports using that output as input. This way the
existing reports wouldn't be impacted while you make things better.
I do like the idea of MoM-style notes fields on the other reports.
For SRUs, I'd love to see the report have the option to be sorted by
package first, and release second - since it saves a ton of time to be
able to process SRUs for multiple releases at once - from an SRU review
and release perspective, at least.