For the (x2) X-Axes, the standard configuration has rollers with bushings on the top and the eccentric nuts on the bottom. If things change (temperature, shrinkage of rubber / plastic, …), this configuration makes it difficult to adjust the rollers with eccentrics; the fixed wrench cannot fit underneath.
Why not have the eccentrics on the top? If the eccentric nuts were on the top rather than underneath, I could easily adjust them.
Any concerns moving them to the top? Does anybody require a picture to understand my question / comment?