Yes, but the question was asked about the 3008w and the answer is NO, a full length queen will not fit with the slide in.
You might want to try this instead. Since the difference is about 5 inches, have a piece of foam cut that's the width of the mattress and 5 inches deep. Now, slide you existing mattress away from the headboard and insert your cut foam. Make your bed and your pillows will sit on the seam and new foam and you'll have an extra five inches at the base.
When it's time to pack up just pull the pillows back, roll up and back your foam insert, slide the original mattress back into place and slide in the slide. How's that?
2012 Windjammer 2008w
2010 Dodge RAM 1500
Reese Dual Cam WDH