I don't normally coast with the clutch in, but I would suggest waiting until you are almost completely stopped to drop into 1st gear.
If you have coasted for a while with the clutch in, parts of the trans have stopped moving and getting into 1st may take extra force. If you were coasting at a reasonable pace with the clutch in, and in 1st gear, and let the clutch out abruptly you could lock the wheel and cause control issues.
Downshifting one gear at a time, and letting the clutch out in between, keeps the trans spinning and keeps your gearing matched to your speed so if you need to accelerate you are in an appropriate gear for your speed.
Thank you for this advice. I will follow this advice and I will not click down to the very 1st gear until I am almost completely stopped (under 5 mph). When I heard that "1st gear noise" while coasting with clutch in at lets say 15 mph I had a "feeling" that this may not be good for the motorcycle.
If you or anybody else would care to elaborate a little more on what is going on internally with the transmission and engine while this is happening I would be very grateful to hear about it and learn.
I actually drive a CB300F but the bikes are very similar. I had a bad habit of upshifting at around 4k rpm and did not realize I was lugging the engine or that it was bad for the motorcycle to do this. In fact I was thinking that I am "saving gasoline" by upshifting early and often and was even driving at 35 mph in 6th gear (I did not know there was anything wrong with this) ......Basically I was in the habit to get up to 6th gear as quickly as I could.
I tell you that it is just this week that I started waiting until 5 or 5500rpm to upshift. It still sounds to my ears that I am straining the poor little engine too much by upshifting at 5000 rpm, the engine sounds VERY LOUD if I wait until then. It is probably because I am accustomed to driving a manual transmission car that I upshift at 3000 rpm on the car and have carried over this bad habit to the motorcycle now.
But no way could I wait until 6000 rpm to upshift, that just sounds like the motor is going to blow up, you guys would have a hard time convincing me that 6000 or above rpm in 5th gear is not unhealthy