Hey @████████!

It really depends on your needs, and a lot of that decision probably revolves around reporting.

Personally, I try to keep things in a single process if I can for consolidated reporting, but there are plenty of times I've needed to split a larger process into multiple smaller parts.

A good middle-ground is the use of the sub-process functionality in the Forms Process Diagram.  It allows you to help keep your diagram organized, easier to understand, and easier to maintain despite overall complexity.  That allows you to branch whole sections of your process onto a separate diagram (I like to think of it as similar to splitting an Excel workbook into multiple worksheets for different parts).  One example I have is a larger HR process that deals with new hires, changes to current employees, employee exit process, and tracking of system crentials.  I used sub-processes to split those four sections into their own processes instead of having it all together on the main process.