This is a minor change to the stock TAZ 5 Extruder Body to reduce flex and sag. This reduces the harmonic ripples on surfaces and edges when you increase the acceleration from the default values.
After installing this and upgrading the stock bushings to linear bearings the only flex that exists in the TAZ 5 X carriage is the flexing of the 10mm rods themselves.
I have attached the STLs and a STEP file that contains everything you need. The full model is also accessible in Onshape at https://cad.onshape.com/documents/fe1f6b97713b43d090c64d57/w/50098f8cde724f1b91f77e39/e/e9d10ba0a7fd45ce864deb69.
All the base models used in this change were based on the FreeCAD drawings included by Lulzbot on the SD card with my TAZ 5.
Print one extruder body and one spacer. Take apart existing extruder and replace body with the new body. Using a M3x60mm bolt attach new extruder assembly to the TAZ carriage placing the spacer between the new body and the back plate.