The optimum speed/power settings will almost never be the same for different users - even with equivalent machines.
For example, what is 100% power? Unless you have a really good reason you should never run at max power, instead you want to run at a reduced power and call that 100%. The tube manufacturer should tell you what current to put through the tube to maximize its life. If you do not have an ammeter then you won’t know what power input setting corresponds to that value. Does your 100% power setting correspond to the real max power that the tube is capable of, or is it equivalent to the max recommended power?
You can adjust most power supplies so that a 100% power setting corresponds to the max recommended current for long tube life if there is an ammeter present. Few manufacturers (if any) of the cheap Chinese machines will take the time to set this up correctly - part of the reason they are as cheap as they are. If you don’t have an ammeter, get one.
Then there is the variability of optics, alignment, and focal length. Even with the power supply properly adjusted a power/speed setting will not work the same as on another identical machine using a different focal length lens.