My family built a 3 bedroom two story log cabin kit in 1980. Lived in a very small metal building while doing so. It was interesting. It was beautiful but in the winter it didn’t keep out the cold. We’d lay down two strips of foam between each log, the logs connected dow-like and we pounded 12 inch twisted nails for connection.
It was some kind of work, just moving the logs, especially the higher you got up. Plus a two-story stone fireplace, where I got to haul the stone up the scaffolding for the mason.
Yeah, I plan on the double tongue-in-groove milling and the foam taping, with possibly a thin layer of chinking along the inner and outer joints. As much as I'd love to go with full Swedish cope logs, I think 8" or 10" D-logs are going to be in the final plans, with 12" or 16" lag bolts. Good R-value, and the inner walls will be flat. Early on, I tried to see if one of the log home companies would tackle Swedish cope outer walls and similar width, load bearing rectangular walls, but nobody would bite due to the architectural difficulties involved. The best that they could do is the Swedish cope throughout, with 1" T&G interior walls.