In general, AC draws a lot, as do space heaters.
You have the time before the Glowforge comes to run a new circuit or switch the 15A for a 20A - though there are considerations and I am not an electrician, even if I did know about your house electric system.
20A, if compatible with your wiring, would not require new holes in the walls or patching or anything and would certainly help your current circuit tripping. Easier than running an additional circuit, be a long way. It might be a better use of the UPS budget to upgrade your house wiring, at least where the Glowforge and computer are.
The solution I used won’t work for everybody; but I have a server and infrastructure man in my house, and he was using a large closet as his office. We decided to move a wall and update wiring. The new office/ Glowforge studio is wired to two 20A circuits. He won’t fill his server rack; but he may run half a dozen machines plus the routers and peripheral electronics, so this made sense for us.