wat5150,
I have a ZForce 48 that the previous owner disabled the reverse PTO lockout on. I agree with you, that turning the PTO off each time you reverse is too hard on the machinery, not to mention a pain because you can't cut that patch of grass behind you. Sure, its a safety issue, but a painful one to put up with.
I've had various things disassembled on my unit for cleaning/adjustment/repairs and would assume that your unit would be similar. With the side panels removed that hold the relays/switches/gauges/throttle/etc., I found that there are push button switches that are activated (pushed in) when the levers are pulled into the reverse position. There is one behind each lever. In my case, the previous owner simply pulled the wiring connector from each switch and taped their ends.
Yours may be similar. If when you pull the connectors, nothing changes, then you may have to run a short jumper wire from one pin on the connector to the other one. It all depends on how your switches are used in the tractor's wiring.
If this works for you, great! If not, then you'll need someone who has more knowledge than I do. Good Luck!