Left a petrified monster (ice and fire), right an armor stand (bibliocraft).
With Dynamic-Stealth

Without Dynamic-Stealth

Have you tried applying the full bypass filter?

After running the modpack, go to config/fantasticlib/reference/entities.txt, and look for likely entity names.

Then in the DS config, add those to the entity-specific full bypass list. In most special cases like these, this should fix any issues.

Looks like the biblio armor stand has already been fixed in my indev version of DS (not sure if that fix is in latest release yet or not).

Ice and fire has a "statue" entity, but doesn't seem to use it for petrified entities, so my previous suggestion will not help. It uses the original entity and does some strange hackery. It doesn't use a potion effect, and it doesn't add any AI tasks.

I'll see if I can detect it via render layers, but if not, then I'll likely not bother with it anymore for now.

This should be fixed in the latest release (104)