A chainsaw has a saw kerf right around 3/8 of an inch, which means it is very inefficient and produces a lot of sawdust. For these reasons, a chainsaw mill is definitely not to be used for optimizing the amount of lumber that you can yield from a log.

Is chainsaw milling worth it?

Chainsaw mills aren't worth the physical and time demands required to mill the logs. Chainsaw mills also cost a pretty penny and can produce a lot of waste in the form of sawdust. However, if you want to mill your own beams for a project, a chainsaw mill could be worth the time and effort.

Is it hard to use a chainsaw mill?

4. Chainsaw milling can be (is) hard on the saw. I use an ms440 which has a 70cc engine, this is really on the limit of what you can get away with - bigger is better, though thinner softer wood is obviously easier going. If you love your saw and hate chainsaw maintenance, this may not be for you.