Huh! I used to use an electric skillet when I did large batches of small PCBs; if that heats on both sides I can definitely see the bit of time save there!
Considering that the pitch on both ICs is pretty easy to handle, more time would probably be spent with the manual pick-and-place. Solder paste does give some very beautiful joints and aligned components though!
Was it mentioned if the kit was just a plain board with nothing soldered, or if the surface mount components were already placed? I wouldn't mind getting everything as just a set of parts and doing all of the assembly.
Honestly, 3 hours sounds about right. I can attest to these things taking time, and time to assemble them right. Wiring harnesses alone can eat up a good chunk on their own just on the crimping.
You mentioned previously getting an oven and a solder stencil made; depending on how quick you're...