When I worked in the 80s doing huge murals we worked with a mag formulation that considered reciprocity , and therefore once we established a set time at one magnification
then we could calculate fstop differences without adjusting the timer unless in extreme changes.
Quite frankly I cannot tell you all how this was done today as my mind is old and feeble.
I am a strong proponent of keeping my times within 10 -18 seconds so that the math will work out in % 's, but since we all have different types of enlargers. and different types of negatives our times may vary.
I do use three bulbs on my enlargers .. 75w, 150 w and a 250 ww depending on the negative therefore keeping my times to the sweet spot as well keeping in the middle areas of my apeture without going to the extremes.
I have heard of some here doing 2 minute exposures which if find impractical.
I also utilize ND to lower the power of my 11 x14 and 8 x10 enlargers so that I am almost always in the sweet spot.
I just finished 4 different negatives for mural silver prints and was able to print at two stops down and between 12 and 16 seconds.
This way I can use predictable % printing as some here suggest to do.
Also I use glass carriers and will adjust the apeture once focused to change density if my time is in the sweet spot.