Munging names like this feels dirty to my plebeian sensibilities, but is this relatively standard? More broadly, does string-munging and Execute get used much in the APL wilderness as metaprogramming tools?

It's common but I wouldn't classify most of it as meta-programming, so much as a workaround for methods the language doesn't support

@B.Wilson it is. As long as no widely used APL compiler exists just feel free to do that.

For Lisp, it is only until compiler only implementation are getting popular people start to get rid of eval

And it was common to expect compiled program to have very different behavior during that transition time