Check out this app, it’s being used extensively for commercial use and has a fair amount of redundancy built into with the Sure Programming Engine. Just ensure that your lock is within about 20ft of a repeater and the engine will take care of the rest
However, given that ST is a “cloud” environment no solution can update the lock while the internet is disconnected. The requirement is a stable internet connection.
Many locks support internal schedules but the current ST environment doesn’t support programming those schedules. We have a few custom DTH’s which have enabled those features on some locks but given that each lock operates differently and that the rest of the event processing happens in the cloud it isn’t a viable solution as yet for ST.
You can tweak app to change the engine’s retry count (to say 999) and it will keep retrying for a long time which is what most folks do who’re using the app where the internet connection is “spotty”.