The keys to easier mounting are minimum diameter center well in the rim, and best technique.

You can't change the rim, but thick rim tape adds to the diameter, so find the thinnest rim tape you can. I've had best results with filament tape, which has the added virtue of being dirt cheap.

Then when mounting, start opposite the valve. When it gets hard near the end, let air out of the rube, go back to where you started, and push the tire to the middle and slide your thumbs along to push it forward toward the valve. Then lift the last section over bushing with the callous at the base of your thumb. Finish by pushing the valve in to free any tube trapped under the bead. Pull the valve back to seat and pump.