I'd be glad to respond, if only to say "I don't know" and perhaps speculate that it may have something to do with the parentheses around the substitution variable code? Have you tried it without parens, or with a [space] character between the parens and the variable code? Robin may have a more definitive answer to chip in here...
As for the email subject-line size, you can already type or paste up to 100 characters in there. Like any text-entry box where the field/buffer size exceeds the visible box size, the box contents just scroll to show whatever will fit within its width at a time, but everything you type is still in there even when you can't see it all at once.
You had never mentioned anything about increasing the actual message-body length in your earlier requests, but that is a hard technical limitation we cannot easily just remove or increase, since we are not arbitrarily limiting that field with any deliberate setting that we could just modify. Perhaps Flash won't take more than ~100k of user input, or perhaps it can't pass that much data to our backend, or perhaps there's something else entirely going on, but it may not be something we have any control over (if it's a Flash or interoperability limitation), and it's never been an issue for anyone until you brought it up and we discovered it was gagging around the 100k mark.
