If I had known the phrase "current doubler" before, I'd have never made this post! Thank you so much. I'll admit, this might get messy - SKB uses uncommon 1/8"/3.5mm TS connectors that convert into standard male 2.1mm barrels with the polarity reversed (though this doesn't matter because the Stage Five can reverse the polarity of every single power output).

I think I can get away with:

https://www.amazon.com/gp/product/B07YJJRGZ9 (2x male TS 3.5mm to female 2.1mm converters)

and

https://www.amazon.com/gp/product/B08W8TC3NJ (dual male 2.1mm current doubler with male 2.1mm output)

If that doesn't, it's only 11 bucks.