Meant to do a little more testing with this and get some good pics, but it’s just not gonna happen anytime soon. So here’s a pretty ugly pic of the nice results I got with Allure Dimensional Adhesive paint. (Keep in mind this is really close up, the fill looks great at a normal distance.) They have several versions including puff, glitter, metallic etc. and the thick viscosity fills the engraving in nicely. I even used it without any masking and it worked fine as the excess wiped off my acrylic pretty easily with alcohol.
The price is about right in the link and I paid less than $4 at the store. (Some online places are way overcharging.)