The mid mount PTO on my Branson 2400 is lever operated indicating that gears have to slide to get it to function. The clutch is necessary to engage (not necessary to disengage) as a result. The lever is marked for the MM rpm or 540/960 selection for the rear.
My 6530 is Independent and the engagement is via electrical solenoid, selector switch operated, meaning that you can engage/disengage it whenever you choose with no clutch action. I do have a selection lever for which of the 3 speeds I want to use and that is to be done with the clutch engaged as you are moving gears. This tractor does not have a MM pto shaft. On any PTO it's best to do the engagement at low rpms to reduce the shock load on the gear train.
Of the 3 PTO types: Transmission, Live, or Independent, Independent is the handiest for most applications followed by Live which is a dual clutch disc type setup on older tractors whereby the clutch pedal position determines whether you have the PTO clutch engaged only, or if PTO lever is on, PTO and ground drive.....this is especially useful in line post hole digging. On my 6530 I have a Live position on the PTO selector whereby activating the clutch pedal, I can interrupt the PTO rotation, whereby in the Independent position it is independent of everything but engine rpms.