Silly Q: still struggling with my project timeline measure 1:1:0

I'm using Calkewalk now for over a decade (or even longer), but still haven't figured out, how to set leadin measures, tempo, bar 1 of the song ... Just a quick example: I have some stems, including a click track, tempo is dynamic (as it is most of the time with music recorded by humans). First thing to verify, the tempo is not fitting - Cakewalk need to be told which content need to be interpreted. Ok, if I now pick a track (with adequat musical content inside) and drag it onto the timelim

M:B:T time 1:01:000 is locked to SMTPE 00:00:00:00 in Cakewalk, and cannot be changed. If the song starts with a partial measure of "pick-up" notes, then the first downbeat will have to start on 2:01:000. For this and other reasons, I do not find automatic tempo detection to be very useful. I've posted versions if the following manual procedure using Set measure/Beat At Now (Shift+M) many times, and still find it give the most predictable and precise results. Easier to do than to describe: