Most modern boilers are microprocessor controlled. I have a Viessmann which is. But to alter anything requires multiple key presses etc. Most people have a laptop these days so a USB or whatever link to suitable software on that would make things so much easier to set up. Does anyone make such a device?
That's how it's done on an aftermarket engine management system (MegaSquirt)I have on the old car, and in many ways engine management and a boiler are similar. Indeed, I reckon a MegaSquirt could be used to do the entire control of a system boiler since it's so flexible. So it can't really be a cost issue.