We've been going back through our backlog and adding support for many things that were left out of the Pathfinder data files before - we added the Bladebound Magus in a recent update, and we'll be adding more in our March Pathfinder update.

Unfortunately the Synthesist is one of the more complex items on that list by far - there are a lot of things the archetype does that are going to be really hard to implement in Hero Lab. :( It's on our list, but given its complexity compared to many of the other items, we may not be able to implement it for a while.

I too play a Synthesist and was looking at Hero Lab.

If the archetype is still unsupported, I have little reason to purchase Hero Lab.

Sythesis Fused Eidolon
 

Any ETA on when the fused eidolon will be implemented into HL?

Class abilites activated
 

Any word on when the class features like the Synthesist Fuse Eidelon and the Quarterstaff mastery getting the Weapon Specialization availability be implemented?