We've never tried it but i think it would make it more comfortable. I think the mattress in the rear is smaller anyway? We have given some though to getting a mattress topper. All in all, after a season of use, the mattress is not that uncomfortable. Seems stiffer in the spring and fall when it is cold out.
2015 Starcraft Travel Star 299BHU Black Pearl Edition
2011 Jayco X23J (traded in)
2009 Ford F150 FX4 SuperCrew