I need advice about Fryette Power Station 2

My question is if the LOAD works when there is a TS (mono jack) plugged into the SPKR OUT of the PS2 when I use it in silent mode?
I would like to use my PS2 along with a custom 8x6 Amp/cabinet switcher which I use in my studio to switch faster between 8 tube amps and 6 cabinets.
This amp/cab switcher has inserts for using all amps connected in via Attenuator. This works perfect with my PS2.
INSERT OUT from the Switcher goes to AMP IN of PS2 and INSERT IN goes to SPKR OUT of PS2.
This way all my amps are affected of the Attenuator but sometimes I would like to use it in silent mode (working with IRís) and Iím not sure if the LOAD works with jack plugged into the PS2ís SPKR OUT.
I wouldnít try before I am sure itís safe for my precious tube amps!
Thank you in advance.