I use a super bright little spot when selenium toning and see the color and density change very early. If doing important stuff I make 3-4 prints of everything and place one print in water next to the toner under the same light so I can see the change in the toning print. I usually print slightly lower in contrast with most papers when selenium toning. some, like Oriental Seagul gain LOADS of density including highlights, when well toned. Others, Like MGIV tone very slowly and once done more closely the resemble the original with deeper blacks and more richness. Ilford Wt is somewhere in between, despite being WT. Forte papers go nuts if you are not careful!