Yes, I liked Fennec in the Mando episodes. That goes the same for Boba, especially at the end when he claims the throne. The entrance, music and no words spoken.....great. I really thought the music played during that scene would have been the main theme for his own show. Jump forward now to TBOBF and this Boba is not the Boba I am use to. I try hard not to over think, critique and criticize, but I can't help it.
Fennec is not the problem, it is just Boba's post Sarlacc escape story line. I will admit I had expectations for him to escape the Tuskin camp (killing some), finding his armor, ship and going after Han, Luke and the gang. Remember the Jedi killed his father and to a certain extent, Luke attempting to escape caused him ultimately to be ingested by the Sarlacc. REVENGE would have been the top priority you would have thought for a bounty hunter.
If I were to order Fennec and not Boba, just to set up with Bo and Koska, it would be incomplete without Cara for me. We all know that story though.
I still have a bit of hope for Boba though. I think he will have a bigger role to play where the Dark Sabre and Mandalore is concerned, but this is Disney so who knows.