I say go ahead and tension the saddle - after 6000 miles you are due.
its not that hard. turn the nut not the bolt. A drip of lube on the bolt will help too. - just do it a little bit like a 1/4 to 1/2 turn at most and then ride and see.
I've use the bolt and laced my saddles - both things help. I keep a record of how far I've turned each bolt and the date I've tensioned them. Helps me keep 3 bikes with 4 leather saddles strait.