I used Frogg Toggs several times. I finally became fed up with getting into and out of the pants in start-and-stop rain. When rain ran down the back of the jacket and under my pack cover, I changed to a poncho that covered the gap between my back and the pack. Avoid a poncho that goes on over your head; you probably will need help to put it on. The
Altus can hang over your pack like a pack cover when rain is imminent, and you just slip your arms into the sleeves and zip up when the rain starts. When it stops, slip your arms out. You do not even have to break stride (but that is a bit driven; take breaks to help your feet and to hydrate!).
Buen camino.