jeez...
why so negative?
with 10 people it would be 14 min.
but if you think your time is too valuable for this, just move along. no need to discourage op for beeing creative or god forbid, giving back to the community on their way.
in the time writing your comment, you could have placed 2 px and made it easier for the community to archive their goal. but no, you choosed to be negative, why?
even though i think that the psu of the 3d printer might get you over the switching time offline usv's have, i'd go with an online usv (voltage & freqency independent)
one missed step and your print might be gone.
depending on your outages you might go for a smaller battery, because you'll have to replace them more often with an online usv.