The micro switch is made by Panasonic and I paid a little bit more for a high et quality part. The button clicks are well within millions of cycles and they also have a thru hole plug, so shear force is transferred to the PCB through the plug and not just the solder pads. I saw two out of about 8000 switches break from manufacturing defects, so the yield is very good.
The vibrational motor is the same part in the LG G4, has gold plated spring mounts and is engineered to last a very long time. Also a high quality part.
The rest of the parts are solid state and have no lifetime limit if you operate them between -20C to 85C. The EEPROM and Flash have extremely long retention lifetimes these days, around 50 years or more.
The battery lasts about 30000 shots, and I did a lot of work to reduce power to keep it maxed out.
The most vulnerable part of the product is the polypropylene cap, which can not withstand an angry player smashing the end of his cue on the ground... it crushes the standoffs and smooshed the foam pad on the motor. I can tell by inspection when someone does this. Otherwise it is very robust.
The silicone housing will not deform even under extreme human strength stress, and will not affect the butt of the cue. It is high quality silicone, not tire rubber, so it will not leave marks.
I dont know why they would be selling parts. I think we've only had a handful of warranty returns, the vast majority being from a butt smash as I mentioned above.