Yeah, LeMaar, and just like having
two XLR Outs for both Pre- & Post-EQ (or for configuring to
STEREO), we also have
two FX Loops for Right & Left (Mono*)
STEREO effects!!
*using the Left FX Loop alone gives a Mono (summed stereo) signal, which is what always goes to the speaker.
For me, these, and the many other Studio modeling and BT control features, more than justifies the expense over and above the regular Rumble 40 combo.

But, ..., but, Maarti, ya gotta use a 'patch', or a 'preset' as
7ender calls 'em, just to turn the Studio or Stage on! (It defaults to #01 Basic Bassman Clean or the last one you used.) And if you use the
7ender TONE App to control your amp, which I've got on both my phone and tablet (for ease of reading and turning virtual knobs), the "Mid Low" and the "Mid High" are just a tap and a swipe away. No muss, no fuss. For my back, that always beats bending over the amp!