Difference between the two circuits
The two different diodes are operating in exactly the same way.  The 1N4148 diodes are simply two parts, whereas the BYQ28E-200 is a single part.  The latter is also able to handle much more power compared to the 1N4148 glass diodes.  While they will both &quot;work&quot;, I'm not sure how long a 1N4148 would last in this application, they are more of a small signal diode, not meant for large currents.
The differences in the snubber (RC connected to the diodes in question) is most likely related to the schematic author's specific ignition coil. There are hundreds of different ones out there and each one of these was optimized for the coil in use.