Hello, this is my first model. Didn't like idea to use metal M3 screw (and I don't have one) so I created some kind of retainer from plastic instead. Works with original model (attached into my STL, all credits to Robert Samples), snaps into hole and fixes very well (tried in PETG for now). It is 2.76mm wide on the edge and 2.9mm in bottom for additional friction to sustain vibrations and other forces. It also has cone shape head to avoid reduction of heat exchange between air and thermistor. Can be disassembled when required without breaking (at least in my experience). I will appreciate your feedback and advices on how to enhance this ultra simple model or why it is not a good idea at all.
EDIT: tried in ABS, scaling initial model (bigger one) to 102% gave me acceptaple tolerances