Schmidt thru Mesa 50/50 -- Dummy load necessary? / Splitting

This may be a dumb question and for another forum, but this amp is $$$. I'd prefer the answer be from here.

I've been carefully experimenting with this set up(short durations). I use FX loop Send > Mix 100% > Mesa > Speaker
Schmidt speaker out not connected. Is this still bad or is the signal not feeding Schmidt power section anymore so it's safe?

Also: quick question.. If I want to use both sides of 50/50, what is a proper and transparent splitting device? Y-cable or something more?

BAD BAD BAD

Never run a tube amp without a load unless you want to blow your transformer.

Very BAD.
You can get a palmer or another type of load box but you need to output the Shmidt to something.
As far as running the 50/50 though one cab, a lot of people use one output normally, and turn the other output volume all the way down while turning the presence all the way up. Make sure you switch up the sides every so often though, or else you will wear out one set of power tubes before the other.