It is basically a big plasma cutter, which is fine, and it's a cool demo project! In my headcannon lightsaber technology began as an industrial tool carried by military personnel in an age when artificial environments full of hard-to-cut-materials were much more the norm to operate in - as a tool, not aa weapon, in the way a modern soldier's knife is very much more a tool, and only a weapon in extremis. Later they became associated with and symbolic of certain fighting forces, some of which eventually evolved into the early Jedi who retained the weapon as a practical tool and a weapon of last resort (when you have the force ranged weapons seem kinda superfluous I guess). So this sort of device would fit pleasingly into my head cannon qualify as a 'protosaber' - not quite a lightsaber but an early device, mainly used as a tool to cut hard materials during boarding actions and sieges (for example), which would eventually lead to lightsabers via centuries of technological advancement, miniaturisation, and development of a culture surrounding them and the people that use them.
Oh yes, I've over thought this. not as much as I've overthought my alternate season 4 of Star Trek Voyager where Janeway decided not to help the Borg fight species 8472, but still... far too much.
I wonder if the style of combat with such a 'lightsaber' would make more sense if it were akin to sword and shield than longsword, sabre, or rapier? I.E. defense is mainly done with a a defensive device ( a cooled shield-like device perhaps) on the other hand. Otherwise the only defense against an opponent with a similar weapon is to dodge, or to strike with total surprise (which brings to mind a very surreal mugging experience: "'Ave you got the time?' Victim looks down, then looks up realising what a fool they've been and expecting to see a knife... only to see a lightsabre ignite instead)