The Mini's (and TL-01's) saver doubles as the mounting points for the tie-rods, so the high-torque tamiya servo saver can't do its job (the tamiya saver in these is longer than the "standard" saver). I don't know of any better replacement of that part. I'm sure one of the guys who own a Mini could come up and say what tricks they've done to stiffen it...
For the Tamiya touring cars I use the Kimbrough Servo Saver Mid-Size Without Holes (part no. 200). Much stiffer than the original saver, and the only reason why I get the no-hole saver is because the version sold with holes won't fit Tamiya's ball studs (the holes aren't big enough, and enlarging them would only crack the saver). Just my 2 cents...
BTW, does the MRE come with the #51000 servo saver (the black Tamiya one)?
TL-01, TB-02R, RS4 Pro 3, TA05R, Desert Truck.