[pwmtr]

You can still restore to a given minute even without one minute WAL boundaries (most of the time). Consider the case where you have a very low write activity and you would be able to fill up one WAL file (16MB) in 1 hour. That WAL file won't be archived until it is full and if you lose your database for some reason, you won't have last 1 hour's data in your backups. That means you cannot to restore any minute in that one hour window. Shorter WAL boundaries reduces your exposure. If you set archive_timeout to 1 minute, then you can restore any minute in the past with the exception of the last minute (in practice, it is possible to lose last few minutes because their WAL file might not be archived yet, but still the exposure would be much less)

DigitalOcean uses 5 minutes as archive_timeout, which is also a reasonable value. In our experience, we saw that most of our customers prefer less exposure and we settled on 1 minute as archive_timeout value.

Roughly archive_timeout defines your RPO(recovery point objective).