Similar to my other z-probe design, but this for mini size. I don't know how to upload the video here, maybe send it later.
Using an optical switch instead of mechanical type, this advantage is no springs reaction force formed when retracting the probe. You can write about a g-code instruct effector downward to rise the probe, and then attracted on the top side by a magnet.
1). Mount - printed layer 0.3, infill 30% be enough.
2). optical switch - I think easy to find as the figure shown type.
3). M4 wrench - Across flat is 2.5mm, 60mm long, must metal type that be to attract by the magnet.
4). 10x5x2 Magnet - Normal not need strong or N35
6). M3 x 18mm x 2pcs
7). M3 nuts x 2