saddle rot - fatal?

In article .com,
hyweldavies
says...

I've had the same. Just clean in and put the usual stuff on it.
I didn't, and wouldn't fiddle with the tensioner. Although I've
admittedly not done the experiment, I've heard that they're best left
alone.
At any rate, there's no need.

I had a really soggy Wrights saddle (as a result of a leaking garage
roof that I hadn't noticed) that I left to dry slowly without slackening
the tension adjuster - it ended up lop-sided with a raised ridge along
the middle because the leather shrank as it dried and pulled tight while
it was still damp enough to take on a different shape.