Yikes... a lot of bad information in this thread.
First: Heat curing is NOT bad. It also, in many cases, strengthens a urethane vs making it more brittle. Alumilite Clear (and Clear Slow) is actually fairly unique in the urethane world because it does cure so hard at a room temperature. Heat curing it (per the instructions on their website...) just gets you to full hardness in 14 hours instead of 7 days. You will not be sacrificing any benefits by curing it that way.
Toaster ovens, etc are not good choices for heat curing. They tend to have hot spots, don't really hold heat well, and you've got an element that's technically hotter than the air temp around it with not a lot of air flow. Same thing with traditional ovens... I get it, they're cheap... but they are the wrong tool for the job.
Best choice is a forced air curing oven. Examples would be by Despatch, Cascadetek, etc. They are expensive but you can guarantee they hold the temp steady and the constant air flow means every corner is roughly the same temp. Even better, they can be programmed to run cycles with a press of a single button. They are also great for drying and curing for stabilizing without a risk of a fire hazard. (I've seen way too many shops burned down by people trying to use smokers and toaster ovens...)
We currently run a TFO-5 Cascadetek oven here in the shop for curing everything and will be upgrading to a bigger one as we look at more high performance ovens. On the used market you can save thousands... so be on the look out there to save some money but expect to pay more than $100
Since buying that oven we use it for everything from drying wood to curing the epoxy on glue ups faster. It's been AWESOME to have.