Naw; for RX and TX applications. Should work to clean up the receive and clean up spurious signals above and below the 11m band. Must admit that I do not know all that much about them . . .
But what I do understand is that by limiting/masking the receiver to a narrower band of signals that the antenna is catching, you can remove that signal load that is just outside of the selected bandwidth. Which will desensitize a receiver - if allowed to pass. Don't know how well the radio's receiver can discriminate; but having a better external filter should allow for greater removal of unneeded signals.
OTOH, by limiting/masking the TX bandwidth it can also keep interference out of any other band and limits it to the 11m meter band. Or whatever band the band-pass filter is tuned/designed for.
A filter that is so constructed to allow TX/RX only between 26.700mhz and 27.700mhz (as an example) would be effective to keep transmitted interference out of the Ham bands above and below those freqs. Allowing TX/RX on the CB band only. It excludes everything else for receive as well.
Chebyshev 2nd order filter
Order=2 Bandpass Chebyshev Filter
Pi: 2.233nF 15.56nH 12.35pF 2.813uH
T :6.225pF 5.582uH 1.125nF 30.88nH
An 4th or even 6th order filter will have a sharper cutoff slope; this means that even less leakage will occur for TX/RX.