Hey Butch,
it was reported that when people burnt up their Makita trim router, it was mostly when they used cutters with a diameter larger than 1/2". As you can see on their web page, they don’t offer bits larger than that for it. In the forum people used 1¼" or even larger surfacing bits, so it’s mainly in this this case that I would be extremely careful. Have big red switch at the door that cuts at all electricity from the installation and a good fire extinguisher (a good suggestion for all other cases too anyway). This is because a universal motor like found in the Makita is slowed down by big loads and in this case at same time, current increases and with it, heat, and furthermore at same time, the cooling fan on top gets slower, and the sparks on the commutator can provide the ignition of melting plastic gases.
Makita knows about this, it says in the manual: