Motorcycle Repair: Rear break squeals a little: 1982 CM450E Honda, motorcycle safety instructor, knowledgable service

Question
I've just gotten my  cycle back from a Honda dealer, where I was advised that I should be using both the front and back breaks.  The idea is that they are both effective but more so together. (I had been relying on the back break as I'm worried about a "high side" fall, since being scared by the motorcycle safety instructor about them.)
This week, I find as the bike slows to a stop, the rear break is squeeling just a little, as the bike comes to a slow speed stop.  Is this a wear indicator, or do I have a developing problem?  The break cable was just adjusted by the very helpful and knowledgable service manager who took pains with my bike. (I trust him.)

Answer
The only time I'd recommend not using the front brake is when the road is wet or there's the potential for loosing traction like on gravel.  The front brake can contribute almost 60% of the total braking effort.  Just apply it judiciously until you get the feel for how much braking force you can get away with.

There's an arrow on the rear brake arm that is the wear indicator. It's not unusual for drum brakes to squeak some when applied.  Normally, it due to lack us use. You can take the brake apart and wire brush the shoes to rough them up some to make it go away for a while.

Regards
Rich