You don't want to raise humidity that high when maternally incubating. The mother snake controls the humidity inside the coils so you want to give her room to go up or down with it. I maintained my humidity while maternally incubating at 70-80 which is the humidity I have it set normally when the snake is shedding.
But, as far as RI... my understanding is, your risk RI in cold and wet conditions - conditions where bacteria thrive best. Therefore, keeping the enclosure dry with the air humid (no precipitation on the enclosure or wet substrate) making sure your ambient temp is above 75F (preferably 80F) you're good.