Soundguy makes a good suggestion I've seen mentioned elsewhere at these web forums. However, as I understand it, the problem for the RT5000 application is that the rear PTO for a Cat 0 accessory turns at 2000 RPM whereas most Cat 1 applications turn a little over 500 RPM.
Therefore, it would seem prudent to slowly engage and throttle up the PTO with a Cat 1 accessory to see IF it can handle the PTO revolution speed being delivered otherwise the Cat 1 accessory could be damaged in the process.
Additionally, the Cat 1 accessory might not get enough torgue at 500+ rpms' to operate properly and/or the RT5000 may stall at the lower end RPM when working at the Cat 1 accessories needed load.
Good luck.