I would probably lean into user testing and user journey’s over user personas a majority of the time. As said above, personas are good for a general ‘finger in the air’ temp check and certainly a very good tool for some departments like marketing and advertising to remember how to ‘sell’ to a certain kind of person and documentation to remind writers what kinds of typical user personas respond to what kind of written language forms in what kind of cadence but for design, UX/UI etc. I find them more of a way for designers to onboard to that niches users. In that way I see them as a tool for designers to help to justify choices if no user testing/research can or will be done.
Here’s a couple of resource sites/repo’s I’ve made over my time:
This is the start of a series of guides, tools, scripts and other mediums to help developers get used to various kinds of design. We focused on user testing and synthesis processes first and are building out more resources as we go.
and if your want some methodology and other exercises to try out you could take a look as some of the work here: GitHub - Erioldoesdesign/opendesign: A methodology for distributed, asynchronous design contributions to software projects
Or you could take a look at the design docs I wrote for OSS design contributors when i was design lead at Ushahidi: Design: overview - Platform Developer Documentation
There’s some scripts and examples of how I did design out in the open there
I hope these examples help! Also drop me a DM if you want so have a video/audio chat sometime 