Eddie,
coax length does not matter if & only if you don't have cmc flowing on the outer braid,
when you do have cmc on the braid the current path is seen in parallel with the load which changes the impedance terminating the coax & changes vswr on the inside of the coax,
the currents inside the coax are always equal magnitude & opposite phase,
anything you do outside the coax with masts chokes radials will be balanced as described in kirchhoff's current law,
when trimming coax changes cmc/rfi in the shack it will also change vswr,
that's hardly a situation where coax length does not matter because it clearly does matter,
not just to the vswr but to how much rfi you get into your base mic / tv speakers,
if you trim to a length that carries less cmc you force more current into the radials or mast or something else connected to the coax braid to keep total return current in balance with current entering the antenna/load,
imho cb antennas stuck in the past, the pre nec days when people had no clue about mast & coax currents,
even the couple that bamboozle with pretty graphics omit the mast/coax making the model useless,
as a result none of them will be installed correctly if you follow the makers instructions,
properly isolating the antenna fork handle style, widing a correct size choke & giving the antenna radials for return currnts to flow where they won't disrupt the pattern fixes all the issues people have with incorrect antenna installs, or it has so far for us,
proper installation & same tip height is an amazing leveler of performance.
