I do the same. deepseekv4 fast for the 90% of the tasks, if it can't lift it, I use deepseekv4 pro. I use crush as coding agent but removed the blocked commands because I also do a lot of system administration. Love it. I use 8 USD in 7 weeks and use it quiet extensively for all sorts of things, programming, system administration, google search replacement, investments, you name it.
Mupdf searches large pdfs much faster. However since I switched to wayland/sway I also use zathura because cut & paste works. Mupdf is an X application but I still use it to search large pdfs. But there is also this plugin but I did not try hard enough to get it running: https://github.com/pwmt/zathura-pdf-mupdf. Under xorg worked cut & paste with mupdf.