Unfortunately, the snapmaker 1 extruder is not well suited to print elastomers, since soft filament can easily escape between drive gear and hotend - and mess up inside the nice extruder housing.
Technically spoken, the short piece of filament transported into the hot end is a pushrod that tends to buckle under certain conditions, which are driven by the applied force as well as elastic properties of material, diameter and length of the rod.
If someone is interested: the math behind this has been developed by famous swiss genius Leonhard Euler almost 300 years ago 
… anyway: in order to have a very soft pushrod here, it must be as short as possible. Extruders like the Flexion or E3D Titan aero take care of that and lead the filament into the hotend from where it leaves the transport gear.
Here comes my simple idea: Fill the gap with something solid … 3D printed, of course.
Taking apart the extruder is nothing for the both-side left-handed. But, with a bit caution and thought, it is neither rocket science. I’m already down to half an hour for full dis- and reassembly, taking pictures in between & re-calibrating.
The filament I used is IGUS Iglidur I150, since this has a relatively high melting point and low friction coefficient. The part is quite small and relatively complex, so better print with highest possible resolution.
A downloadable STL file is here: https://www.thingiverse.com/thing:4309899