ILIKETRAINS
Yes, I also thought of OCR capabilities, but it would become quite resource-intensive, especially for legal text PDF.
I was taking an example from softwares like Dangerzone, that’s why I guessed it was maybe the reason.
In Acrobat Reader (desktop), while in Protected Mode, the basic search function is only able to search in the current page; advanced search can scan the whole document but it seems to be hindered regarding speed.
We will see.