I’ve wrestled with a similar question. At least for now I don’t trust anything wireless from both a security and reliability point of view so I’ve hardwired as much as I can to a structured control center. Generally I use 1-wire to read sensors and DMX to control things. An EDS LAN<>1-wire bridge connects the sensors to HA. I use a DMXKing Artnet<>DMX bridge to control lighting and also low voltage relays that control other stuff like zone valves.
When I have a lot of non-1-wire sensors close together, such as current or pressure sensors I aggregate them as a single 1-wire device using a Teensy MCU to emulate a DS2450 16-bit 4-channel A/D. If I had a bunch of reed switches as in your case I’d probably use the DS2408 to read up to eight relays at a time. A single 1-wire bus can connect to all the COTS and emulated sensors. The HA 1-wire integration supports both devices as well as others. With three wires you can get plenty of power to the sensors and cover your whole house.
I do use Zigbee to control things like individual track light or recessed light brightness or color but I also wanted a fail-safe/failover mode that doesn’t rely on HA for anything in case something goes seriously wrong. If HA fails I give up “luxuries” like light dimming and other automatons but 3/4-way light on-off control and HVAC works.
Of course I’ve left a lot of details out but this is the overall approach.
EDIT: To clarify, the DS2450 access from HA is via owserver (a component of OWFS). OWFS supports the DS2450 and HA supports owserver . If you wanted to use e.g. a Raspberry PI as the physical 1-wire master then I don’t think the DS2450 would be supported. Since I use the EDS 1-wire<>LAN bridge and talk to it via owserver I can communicate with a DS2450.
As stated in the HA docs for 1-wire, many use a DS2438 Smart Battery Monitor instead of a DS2450 because the DS2450 was obsoleted by Maxim a long time ago. Emulating one is pretty much the only way to do it now.