Prusa Enclosure - Modified Stabilizing Spacer for MK4/MK4S

Structural remix to reduce printer vibration on large prints while using the Prusa Enclosure.  I used  PETG filament w/ Organic Tree supports.   Thirty (30%) infill may be overkill.

Trimmed the front brace wall to ensure printhead loveboard clearance while printing large models by using a negative volume object.  I also split the model to ease prototyping the clearance needed for the loveboard.