Mark IV: "Normal" FX loop vs "Switchable" FX loop

[Noe5]

Hello everyone,
Owner of a 1990 (I think?) Short body hardwood/wicker grille Mark IV combo.
I love this amp, I look at it, stare at it, dream about it, wouldn't trade it for anything in the world (and I own a 100% original 1956 Bassman and 1957 tweed Deluxe).

Anyway, back to the topic: do any of you use the "normal" FX loop? If so, what makes it appealing vs the switchable FX loop? Are they both series loops? Can anybody use both at once?

 

[Noe5]

There she is by the way...

 

[mystidream]

There she is by the way...

Wow, she's a beauty! I used to have a couple Mark IV A's and I'm pretty sure you can use both loops at once.

 

[Noe5]

Hmmm... I figured there must be a way to use both, but the click switch labelled "normal"/"switchable" just doesn't allow that. Any way round that? If not, does anyone use the normal loop??

Noe