How can I keep the Compiled Templates from caching during development?
If you're in devMode, then Twig's compiled templates will be regenerated on every request.  Otherwise, they'll be regenerated when Twig sees that the source template's date modified timestamp has changed.

As of PHP 5.5+, PHP's opCache is enabled by default, which might explain what you're seeing. If you're in development, you'll want to disable that to make sure PHP isn't doing any caching at the byte level.