Fuji Transonic 2.8 2016: rear derailleur hanger direct mount or standard? I have a Fuji Transonic 2.8 from 2016 that has the following hanger installed:

https://wheelsmfg.com/derailleur-hanger-215.html

I am replacing the short cage Shimano 105 rear derailleur with the medium cage version to be able to use an 11-34 cassette.

Now the previous bike mechanic installed the short cage derailleur with the b-link removed, so clearly it was being treated as direct mount hanger, but I want to make sure that I should do the same with the medium cage derailleur. Couldn't find any documentation anywhere on which type the above hanger is, found a bunch of sites trying to explain the direct mount vs standard distinction but they all look the same to me. I want to make sure I don't remove the b-link by mistake when it is really needed.

Thanks.
TLDR: You have a standard mount hanger, leave the B pivot on the derailleur.

Looking at this Wheels Manufacturing page, what they call 'direct' hangers put the M10 mounting hole further to the rear than 'standard' hangers.

I believe that with the newer groupset series that introduced 'Shadow Technology' (moving the derailleur in and behind the cassette a bit) Shimano wanted the B pivot further rearward than previous designs and added the B-link to do this. They provided for original bicycle manufacturers and third party hanger manufacturers to make 'direct' hangers by making the B-link removable. 

If your hanger goes straight down it's a standard type, use the B-pivot. If your hanger goes down and rearward at about 45 degrees, and there is a horizontal separation between the axle and M10 mounting hole of 1-2cm it's a direct type, remove the B-pivot.