You could just use an image. I’d imagine it’d be a lot simpler and would work with AspectRatioConstraints very well. The only drawback is it couldn’t be dynamic unless you wanted to use some sort of spritesheet.
I suggest not going for aspect-ratio constraints, but rather using pixels for crosshairs. What I like to do is to make the crosshairs frames dependant on the AnchorPoint for the positioning, and pixels for the scaling.