Scott,
Not seeing your trailer, I don't know how much space you are dealing with or if it's something you stand on or not. Word is that Rhino and LineX get very slippery with grease on it - I've also read about others saying it's a pain to clean.
I'm envisioning that your smoker opens to the rear of the trailer and you work off the ground, but it has about a foot or so of space from the smoker to the rear of the trailer. (Just the image in my head) If so, have you tried putting anything down before the cook? I'm thinking one of the trays from an autoparts store for oil changes. I put one below my BWS for that reason - and it also catches all the coals/ash as I open the firedoor to reload. BWS and SW are very similar in this aspect. This might be something you can cut to size with some tin snips and removable for cleaning.