Thanks for your reply! Wise to check assumptions.
Yes, written a compiler in common lisp and various toys in scheme. Spent some of yesterday porting functions from SRFI-1 to Shutt's Kernel which is pretty close to a lisp. Interesting that you claimed first class macros, they're usually second class in lisps.
I like scheme because I'm far enough down the compilers rabbit hole that language syntax looks like obfuscation in the way of the SSA representation. Writing the syntax tree directly is attractive there.
I find macros pretty confusing. Common lisp has straightforward behaviour but needs a lot of ceremony to make them reliable. Scheme's hygienic rewrites look simple but I don't understand the machinery behind them. Lexically scoped fexpr have obvious behaviour and implementation hence the interest in Kernel.
Which is to say I'm not disputing the lisp ~= lua premise from a position of total ignorance. The semantics look pretty similar to me. Lua doesn't have control over syntax, in (reader) macro sense, so perhaps it's metalua I should be equating to scheme. As above I'm not very focused on syntax.
I also write a lot of lua so am keenly interested in the distinctions I'm missing in the above.