Are control boards switchable? I am interested in buying a larger printer, either a Sovol SV01 or a Sunlu S8 (or something else similar).
What I am wondering is, can the control boards and LCD displays be changed to better units later on?
How much are parts interchangeable?
Can the frame, steppers, extruder, base-heater and power supply be run with any control board which has enough outputs? How does this work?
I'm particularly interested in adding silent stepper drivers and BLTouch later on, neither of these units are very popular so not a lot of after market parts are out which list compatibility.
Yes. Stepper motors, heaters, temperature sensors, fans, etc... are all standard parts. Pretty much any control board can be used with the hardware from pretty much every printer.
Some more expensive printers might use more exotic parts (especially temperature sensors), but on the budget printers you're looking at I would be very surprised to find anything non-standard.