I've used glass overlays on radius back TD risers to tie the two limb pads together and it definitely makes it stronger. but it can split where you drill for your pins and inserts sometimes.
I prefer using a linen or canvas phenolic to wrap the riser back myself. I have used the Core tough and Uni weft as riser limb pad overlays and full overlays successfully , but it ain't very pretty. I went over it with wood to dress it up. Kirk