The UPS notaries are there as a loss leader for UPS. It’s to get you into their store hoping you’ll use them in the future. There’s also UPS corporate who’s risk management won’t allow for certain engagements, such estate or end of life documents. I’ve observed non-notary employees filler out the journal and certificate, then call the store manager to perform the notarization.
In Texas there is no required training or testing. There are only two requirements to become a notary; First no criminal convictions, second the ability to fog a mirror.