Never used a rdo on a shield, always found them to small for my hand. But that aside, if your owb is kydex cutting the out for the optic can be a possibility , not so much with leather. I've done it but it's not pretty. I have an old fie, pre heritage sa 22. Mounted a original tc mount and scope, cut the leather around the base with the scope exposed. works for what I use it for but adds no protection to the optic. Most cut outs do the same.