Thanks for the responses, and let me add a bit more detail!
Concur totally with the safety concerns when storing or parking the tractor end of day...my implements are always lowered, with no load on the hydraulics.
Yet going out on a limb, suggesting I'm not the only one to go down in history, who has ever had implements raised with the tractor off!
My situations are while working. I'm actively on and off the tractor dozens of times during the day.
Tasks, such as cutting trees or clearing slash create need to use the chainsaw, gather loose branches, hook up chains, etc. If it's expected to be more than 5-7 minutes of effort, I idle down and shut off the tractor.
I leave the box blade for rear
ballast, up out of the way, rather than lowered to the ground during these short shut downs.
Same with the FEL, with the grapple normally closed for travel and maybe knee level above the ground.
The question is if anyone from the TBN Brain Trust is aware - conclusively (not conjecture) - whether shutting off a tractor while the hydraulics are loaded is verified to be any more adverse for hydraulic system components, compared to what they receive during standard duty cycles with the tractor operating.