My apologies if the comment came across as negative. I just meant to say that I didn't want to exchange one set of shell quirks for another. But using {$x}-style grouping is a fine solution too. And in any case I'm sure that bash has a lot more quirks than Elvish :-)
So I'll definitely do more testing with Elvish and see what the overall experience is like. Coming from Solaris, we still have a ton of ksh scripts in our shop (with people working on them who have very different backgrounds and scripting skill levels). Something with less pitfalls than bash would be great... Thanks for putting in your time and effort!