I have been using the Hydra conversion for a while. It works very well for me with different coils.
Only coils that are very fully wound e.g. eSun ABS+ made problems until a few meters were printed. Therefore, I currently have a combination of the two versions (with and without the lower guide fins) slot 1 to 3 I use with guide fins, slot 4 I use the version without guide fins. So I can use such (problematic) coils initially in slot 4. Later, when a few meters are used up, I can use this coil in all slots.
Since then I use only big spools (750gr to 1000gr).
Cheers WR