Make contact sensors with external connections available individually without magnets. The external connection can be used with other contact ‘switches’. Case-in-point, a completely wired home (windows, doors, etc.) for an older style alarm system. Such a contact sensor could be applied to the existing alarm sensor wiring making the alarm system smarter. All of the sensors could be applied in a central location without the need for applying to each door and window.
Those could also have other uses, such as a water sensor (just run two bare leads to a non-conductive surface, tack them down, and any leaking water would make a connection). They could also be connected to a simple switch to allow manual triggering to activate a routine (e.g., a physical switch for a Wyze bulb, for example).
I did just that myself. Popes the unit open and replaced the reed switch with a short bit of wire. Then I tied a zone of windows to it. While doing this to multiple devices, I noticed that a number of the antennas were very poorly soldered, and some snapped right off. A quick reheat of the solder took care of the problem.