GameStop trade for Xbox One X deal...

Sorry if it’s been asked before but I didn’t see any info on it.

GameStop claims to be offering trade bonuses towards the X, $200 for Pro/Switch trade, $150 for PS4/S, and $100 for OG Xbox One.

What I’m wondering is if anyone knows if they’ll stack. Like, I have a PS4 Pro I may part from as well as an Xbox One S I’d be upgrading, would I get $350 towards it or would it be the $200 for the Pro plus the base value of the S?

The employee said the only trade in deal for an X1X at the moment is you get a voucher for either $50 or $100 (I forget what she said) on top of the value of the one system you are trading in. You can trade in multiple systems but only one of each kind.