I experienced some tilt to my x-axis after my linear rails conversion - likely a result of the material of choice being PLA+ rather than something that can handle heat better.
Instead of just reprinting the part I opted to over-engineer it with some heat-set insert support. I added heat set insert support for 3 of the 4 motor corner holes in addition to the 2xM6 factory bolts. I had to leave one motor corner unsecured to leave room Use at least a M3x45 to secure the motor directly to the printed piece. In total there are now 5 separate bolts securing the motor and some additional mass to soak/distribute heat - yes I will eventually reprint these in ABS or something more ideal.
The author remixed this model.
I remixed the original top right bracket piece to support heat set inserts for the original bracket mounting M4x6 bolts and three pass through M3x45-50 bolts to provide additional stabilization of the motor. To accommodate the inserts I widened the part 1mm each side and added some chamfers consistent with the existing styling.
It is a direct replacement for the original piece. If you wanted to use this component you would print this instead of the "HOON - Ender 5 S1 - LR - Y Gantry - RIGHT UPPER.stl"