I haven't been able to figure out how to duplicate the
setup we have with apache2--namely, PHP disabled by default, by
overriden on a per-directory basis. I've tried php_value engine 1, but
that doesn't seem to work.
AFAIR, there's no php_value, but php_admin_value instead.
In any event, I'm concerned anything I do to
make the htaccess files compatible with apache2 will break compatibility
with apache1.3, so I won't be able to have everything running in
parallel for testing.
With all the above being said, I'm not sure you could enable the php
engine in a .htaccess. That would need some testings, I guess.