Not sure if anyone from Garmin looks at this forum but would it be possible to allow us, the user, to add a distance to the list.
Or maybe just add 10 miles to the list as there are quite a few races now at that distance. :o
It's not simply a case of adding an entry to a list, though
The problem there, at least for the Forerunner 230/235/630/735, is that the device itself – but not the cloud-based Garmin Connect service – is responsible for detecting new personal records “over several typical race distances”. Allowing the user to add a custom distance to the list will neither make the device look out for the fastest time over that distance when tracking/completing a run, nor make Garmin Connect do additional post-processing after the activity data has been uploaded.