This is well said and I respect your statements.
But remember the OP and the questions he asked. Apparently this is a new fellow and he was asking what setting he should set when he makes the frame larger, say from 8x10 to 16x20.
I know you were trying to help, but you mainly stated what you did and what you would. The experience from someone with 30-year experience vs someone just starts out is so different. I have seen this happened so many times, so I stopped asking newbie questions any more (I'm still a newbie in many things). We really need to step our feet in the OP's shoes to see how we can help him progress.
Actually B&W is technically simple. With the safelight, open trays, it is quick to have several test strips made. Assume the OP knows the basic photo optic theory, when he tries to print larger frame, he should increase the exposure. This can be achieved by openning up the aperture or increase the exposure time, or the combination of both. Changing aperture may impact the VC and longer exposure time may impact the reciprocity. Of course he can make 5-6 test prints and make a subjective judgement. But a very simple meter, like the EM10 ($25), can read one important highlight (negative), then helps him to achieve the same measure with a larger frame. EM10 does not need calibration and it is objective, not subjective. And this can clearly cut down 4 test prints.
The hurdle for color printing is even higher. This is one of the main reasons home color printing is not very popular. Color analyzers can help greatly if the users know how to use them. I believe at places like Costo, there are auto light meters in the Noritus machines and there is very little human involvement. The print quality is very acceptable.
All the devices are tools and they do not take out the fun we can have, but they certainly lessen the frustration we experience.