I'm assuming CraftTweaker integration, but being able to modify it from other mods would be a neat additions too.

That might require changing the code a little bit, trying to make it as most compatible as possible. One way I've resolved it myself is using this code (will require changing to Kotlin):

Optional<IProperty<?>> ageProperty = block.getDefaultState().getPropertyKeys().stream().filter(property -> property.getName().equals("age")).findAny();
ageProperty.ifPresent(property -> this.ageProperty = property);

which would find you the property named age. One note about that though, I've noticed that ExtraUtilities mod is using property named growth instead.

I'll see if it makes sense to add more compatibility. I don't think Extra Utilities would be an issue because most of their plants don't seem growable by bees.

Compatibility is coming soon.

You can check thedarkcolour.futuremc.api.BeePollinationHandler for more information