My question has been closed on the grounds of "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." Whoever closed my question, didn't seem to have read it, as it was not about the use of the devices. It seems quite obvious that both devices (a UPS and a portable power station) are intended for different uses (heck, it's in the name), I've never questioned that. Yet, from a technical perspective they are very similar, which is the premise to my question. It is a question not about use, but about specifications, which is relevant for any design.
If the question for whatever other reason does not fit in electrical engineering, migrate it to some other place.