If I install octopi/print on my 3b+ am I able to use the pi for more than just octopi/print or does the pi become dedicated to this project.
Currently I have my 3b+ running PiHole and an instance of chromium that is casting a dakboard screen to a monitor. I would like to keep running those and octopi/print on the same unit if possible.
I do not mind ungrading to a pi4 for extra resources if need be.
Then you would have two raspberry pi's, so why not have one dedicated to OctoPrint?
Sending a gcode file from the raspberry pi to the printer is somewhat timing sensitive. If one of the other services has a "hickup", it could affect an ongoing print. The chance of that happening, especially on a Raspberry Pi 4, is fairly low, but not 0.
To answer your question: sure, it can be done. But if you ever need to troubleshoot something, you are making your life unnecessarily hard by doing so.
I think specifically with PiHole they don't support it running on the OctoPi image due to conflicts - both want to run on port 80 for example, you will have to know how to create custom reverse proxy settings.
I've also heard with PiHole it can be quite resource intensive at times, which might impact your prints at some point. Obviously that doesn't stop you experimenting with it, to see what the usage looks like but its a risk.
My advice would be to get a Pi Zero 2 to run one of them on. You would end up with 2 Pi's if you buy any other model, so you can keep them separate, but neither really need the extra power of a Pi 4 on their own.
I appreciate the feedback from you both.