Congratulations Dave and SWMBO.
Is there room for expansion, or are 2 modules enough? I hope the projects are compatible even though they aren't a matched pair.
The motherboard may not be able to support additional draw on her supplies.
Also Dave might need to shift to a new enclosure with extra expansion bays for the new module.
Do NOT TRY TO PLUG THEM TOGETHER - even though they're not a matched pair, it may have unexpected consequences.
Having seen Dave's old 4-wheel 'buss' in previous videos, he should be ok, but will need to add an extra 'riser' for Huxley in the rear.
Edit: Look out for leakage of electrolyte over the first year or so.