I replaced mine with aluminum a year or so ago.
https://www.trailmanorowners.com/for...ight=bed+slide
My only comment is that 1/4" flat bar seems awfully thick, and I see no reason to go there. I considered using 1/8", but finally used 1/16". I think the plastic on mine was 1/16" thick, so compatibility is good. And 1/16" aluminum flatbar is plenty strong - you will rip the screws out of the MDF bed base before the aluminum bends.
Most likely no problem with 1/4", except that you will have to use longer screws up into the MDF bed foundation. Handy, since I was able to re-use the same screws in the same holes.
Bill