Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:5363733.
Ender 3 V2 BL Touch mount, which mounts using the existing V Roller bolt plus an additional M3 bolt through the bottom of the carriage.
If you wish to use the plotter attachment, the model is designed to require 3x M3x3mm heat-set inserts to provide a sturdy thread for the bolts to attach to.
I didn't need any supports to successfully print this model. To obtain maximum strength, lay both parts flat on their left sides. Print at 0.12mm resolution with 23% gyroid infill.
A modified part is provided which does not require the use of heat-set inserts, but I have not tested it.