I agree 15 amps is absolutely on the low end power wise. But honestly while the time of the cut is an attractive figure, it isn't really the limiting factor for home use. Set up, physical energy, and log handling is a bigger deal with these lightweight setups. But cut time matters for sure.

I do like the idea of having a power boost to up, say a 15 amp extension cord to maybe a 20 or even 30 amp motor. The power is available since it would typically only be running, say 50% of the time. That is to say maybe 5 minutes per cut then 3 minutes off with longer breaks periodically for a simple one person operation. Very roughly speaking.

I'm thinking that it would be out of the range of a capacitor to hold that long, but there might be ones out there that could.

A battery setup with inverter would certainly do it, but that's more weight, expense, and cost, by quite a bit. A lithium battery with inverter isn't completely out of the question though.

Anyway I guess a person could make that decision for their build.