I have this one;
https://www.amazon.com/Lionladder-Te.../dp/B07WSTF6PD
I bought this ladder after I bought the 5th wheel since my other collapsible ladder was too short and my folding 12' A frame ladder was not feasible to carry with us. Some thoughts on it;
It's fairly heavy so trying to maneuver it around the trailer can be cumbersome on unlevel ground. It telescopes so if you're not careful you can get your fingers caught between the rungs. It has rotating feet which make it more stable and the rubber ends on the top won't mess up the trailer finish. It has been dependable for 2 years but doesn't see a lot of use.
It's overkill to use to clean the windows so I just use a window washing tool with squeegee. I have slide toppers so don't need it to get on top of the slides any longer. I've used it one time, on this trip when the awning gimp started coming out of the slot on the side of the trailer. Other than that it takes up space. I guess bottom line it's not convenient for a lot of things but there are things/times that really require it so, like all the other "what it" stuff, it will sit in the pass through until I need it.
Depending on the situation you might find one of the 7' aluminum collapsible ladders fits. I had one of those with my TT and it was great. IIRC 7' was the longest and it was difficult to use (a little short as am I) for cleaning slide tops.