I use PDF annotator and I'm quite happy with it. I don't write in my rpg PDFs very much, though, but it should work well for that purpose.
One added benefit is that it also lets you combine PDFs together or make a smaller PDF out of a few pages of a larger PDF. For example, if you just want the stat block for X monster, you can make a 2 page PDF that just contains that.
Did you already research PDF Annotator? https://www.pdfannotator.com/en/how#type_write_highlight
I've never used it but it looks like it might do most of what you are describing. Best of luck in your search.
PDF Annotator, Foxit Reader, Adobe Reader, any number of other options, or the Preview program built in on any Mac.
if you need A LOT of features, PDF Annotator has them, only downside: Their license model is quite expensive and you should opt-into the upgrade assurance, otherwise you might miss major version updates.
If you need light-weight editing, Drawboard or Xodo. Foxit Reader also has some PDF-annotation features, but they aren't as pen-friendly as the other mentioned apps.
As long as you're a student, there's also a student discount for PDF Annotator (-50% iirc). But as long as apps like Drawboard or Xodo fit your needs, there's little reason to go the expensive route.
I gave up on OneNote over ten years ago. I did not need to be connected to anyone.
I switched to PDF Annotator. It has basic pen and pencil drawing tools for doing engineering sketches. You can make huge PDFs. Not sure if you could get basket ball court size document like they had for the Manhatten Project but there is plenty of room to work.
I just open up a blank document and start sketching. It is also good for reading and making notes on PDFs
Everything is in a simple PDF file readable by everything.
I used it to take hand written class notes on an Intel Duo Dual Core X61 Thinkpad tablet at the time. It is quite nice and clean on a modern computer. I upgraded to a 22.5 inch Artisul Pen Monitor.
I have been using PDF Annotator for years now and I have try others and nothing has come close to my level of satisfaction. You could try the free trial and decide for your self.
This is a pleasant coincidence. I've been thinking about making some changes to my digital workflow.
I'm using Mendeley right now, but planning to switch to Zotero, as I'm not happy with Elsevier's decision to encrypt the database.
I'm also looking for a PDF annotation/reading management software. Something to make and organize digital notes for the PDF papers I read.
I've been trying PDF Annotator and it's okay, but I haven't shelled out the $69.96 for a license. This is something I'm willing to pay for a solution to, as long as you aren't bending me over with Adobe-level prices.
Anyways, I've never really been an early adopter, but I'll plan on giving this a try when I get a chance.
The two most powerful, but more expensive, pdf editors both have custom stamps. PDF Revu is the most complex but PDF Annotator is probably good for what you need. Here is the page about custom stamps for PDF Annotator: