With this mounting piece, you can neatly organize either three or five WAGO 221 inline connectors into a compact cable assembly. Cable ties (up to 5 mm width) are used to provide effective strain relief.
The bottom part is identical for both the 3-pole and 5-pole versions. If you want to connect five wires, you simply add the top cover.

I printed the parts in PETG, and no supports are required.