No problem!
We did the same thing, wrote out a small, basic set of guidelines outlining why we didnt want anything on social media or big tech clouds among a few other things.
Most family downloaded signal straight away which was a bonus to be able to possibly fuck off messenger in the future.
As long as you make it as easy as possible (within reason, dont bend over backwards if someone doesnt want to comply for no good reason) for others within your boundaries then it will end up being mostly painless.
Also congratz on becoming soon to be new parents! Sleep as much as possible now! Haha… Aha… Ha…
Ive had a galaxy tab for a bit over a year now and use Notewise.
Its not foss but fuck me its the most comprehensive note app ive found for use with pen.
I use it to mark up construction plans, edit PDFs, sign documents, design things with its protractors and rulers, take notes, read manuals, its really above the rest in every way.
I do use Joplin for general text note taking in a notebook style but Notewise for anything and everything else.
edit - it also saves documents in i believe vector format so you can fully zoom in to your writing / highlighting and its never blurry. I found that samsung notes was absolutely horrible after you exported anything to pdf or image.