Please Assist with Jail Bird Adjustments

I bought a Jail Bird from Mature Metal for my husband/slave and started with him wearing it at home and during dinners out. Recently, I’ve had him wear it around the clock for several days now. The issue is that he’s getting “ball burn” (his term) on the underside of his scrotum near the base ring. He has to wake up a few times overnight to shift the cage and apply moisturizer, as well as use the bathroom, to find relief. Any advice? The 4-inch cage length works well—I can barely manage to put it on when he’s soft. The base ring is 2 inches with the maximum 1/2 inch gap. Could the base ring be too small? I saw on another forum that Mature Metal suggests a double base ring tends to be more comfortable than a single one. Would having MM convert it to a double base ring improve things? Thanks, ~Alex