Very well done and yes, I am curious. Good to see someone who's actually done that upgrade to Sequoia. The thermal sensor bit went over the top of my head (maybe a memory-fail from my time squeezing Catalina onto mine) but is it a function/result of the SSD you used?
This image is of my Mac's basic report regarding the clock speed and it too shows 700MHz
[image|3437533]
... and although I've never tried to dig deeper it pretty obviously functions correctly. I suspect misreporting but took the stance: "Does it matter?" Answered myself with a "No, it's doing all I need regardless of what it's indicating." so I ignored it for the last four years.
The one bit that does intrigue me is the question of the ACTUAL max RAM that will work. I have 6Gb, a 4Gb in slot 1, a 2Gb in slot 2 - but has anyone tried to put more in?
I don't have any more 4Gb sticks, or I would try it and see.