I'm not familiar with your tractor model.
Does it have a 2-stage clutch, an independent mechanical pto, or an independent hyd pto?
The 2 types of independent your clutch will have no effect on the pto. The pto lever is the only thing that will ever affect the pto.
The 2-stage type generally don't have a pto brake, so don't think this is what you have? Push the clutch in 1'2 way, & the tractor stops moving. Push it in all the way, & the pto stops moving as well.
The independents with the pto brake are good in some ways, but if they are abrupt, sudden on sudden off as many hyd especially) are - it can be very hard on the equipment, esp heavy loads like brush hogs. Best to start & stop them with the engine near idle, if you can.
Your 7100 had no pto brake, my BiL has one. His did not have a live pto at all, any time you pushed in the clutch, the pto as well as the tranny was disegaged.
Since I see you are talking about a hydrostatic newer tractor - you likey have an independent hyd controled pto, where only the pto lever itself is used to control it? Your 'clutch' won't have any effect......
But again, I'm not familiar with your tractor, or hydrostats for that matter, so ......
--->Paul