Funny you say "High heel"... I have a personal rule for floor outlets... "Must be able to support 350# woman standing on sigle high heeled shoe..." Which rules out most cut in versions unless proper blocking is installed. My reasoning for it, a guy I used to work with installed one, and along comes the movers to bring in a client things and one wheel of a 2-wheeled cart pushed the box right through the floor. I had to go fix it, with the 350# client standing there saying, "I could have put my foot through that."
Some cut in versions are actually a 1 gang cut in, and suposedly listed for the purpose. (Off the top of the head... Cant remember the brand, but don't think the make a 2 gang version like it.) I won't install it if I can't get bracing up under the sub-floor, and under the ears where they sit on finish, and a heavey brass plate is installed, spanning the weakend opening. To do otherwise, you would have a sort of cantelevered portion of sub-floor on one or more sides of the box. Just waiting for that 350# woman!
Either way, I think a good replacement for your current situation would be a suitable box and properly braced.
