If Memfault ever want to end the standalone external tool supplier gambit and return to being in-house expertise, sounds like they could be very useful there. Not because Garmin's BT is so terrible (it has improved a lot but still far from perfect), but because Garmin seems to be the smallest living company that still builds their own stack down to the lower levels instead of hitching a ride on something like an Android fork.
The proprietary RTOS that runs on the watches is a super cool embedded system dating back to the earliest days of the company. It grew across all the product lines - watches, nav units, aviation equipment, marine chartplotters/sensors, etc. I remember once stumbling on some code written in the very early days by an engineer who went on to be the CEO while I was there.
It was a fun system to work on, and had an impressive amount of code sharing at the OS-level across platforms as tiny as Cortex M0 systems up to large multi-core ARM SoCs from TI and other vendors.
1. Extremely talented Bluetooth engineers. Chris and Martijn were second to none.
2. Very good diagnostics tools built in house. When a user complained of connectivity issues, we could take a snapshot of the state of their Bluetooth stack. This gave us amazing insights into what was going wrong- more often than not we found that iOS and Android were doing something unexpected (we had lots of workarounds for their bugs). FWIW a few of us went on to start a company to build more of those hardware debug tools: Memfault (W19).