[High5er]

I have to agree with a lot of the comments here. We've used our RV(s) recreationally for a couple decades and now for the past few years have been full time. I've never found a mattress topper good enough to use with the stock RV mattress. Many mattress stores have their own generic foam/springless mattresses for sale that are a great alternative. They're generally inexpensive and are much lighter than spring/latex/purple mattresses. They also expect you to haggle a little bit, so you don't need to pay the full retail price. I think we spent $400 to replace ours and we love it. We had a sleep number for a few years, and they're very light weight, but with temperature and elevation fluctuations, they require some management. You also need a generator or shore power to adjust them.

As for the slide struggling, I agree with those comments too. Your slide motor shouldn't be struggling with a mattress topper. If there isn't a massive amount of weight under the bed, nothing is binding/blocking it and you have adequate voltage to the motor I would expect it to perform normally.