Some guys require more of a conditioning period than others… some none at all. The key point here, if you do experience irritation and redness you should take some rest for a few hours or overnight. The sooner you rest the sooner you can resume wearing again.
The biggest contributor to irritation in the area occurs when there is excess skin left between the silicone ring and the glans. When the underwear and pants compress the glans it will trap the sensitive skin of the frenulum and pinch. Friction will occur when walking which causes the irritation.
When putting on the Innerwear you can draw the excess skin back into the sleeve by holding the silicone ring on the underside of the glans with one hand and use the other to pull the skin at the base of the shaft near the ball sack. Make a final adjustment of the silicone ring to seat it directly behind the coronal ridge of the glans.
As we have been working on your resizes at the support email I am not sure what your history is.