On 15 meters, Ed, you would have more of your SSB signal out of the band
on LSB than when you are on the usual mode of USB. What you have to
really watch on 15 meters (and 20, too) is the upper limit of the band.
There seem to always be stations above 21347 and often also above 14347,
although less often than on 20, probably because there is more
non-contest activity on contest weekends on 20 than on 15. A few years
ago, I and many others, got OO cards for quick replies to a DX station
operating about 14348 in a DX Contest and I have been much more careful
about that since then.
Hope to see you this weekend as guest op at W4AN in ARRL SS CW. Have