Does anyone know how many times you can disconnect the BT hub's from the DSL line before the DLM starts to kick in?
Will it still kick in if you do a 'disconnect' via the hub manager before physically unplugging it?
I prefer the method you are suggesting as a soft disconnect by using the hub to disconnect internet before actually taking the rj11 cable out of phone socket never found that caused DLM any problem
One disconnection will not cause any problems. It is repeated disconnections that get interpreted as a fault that causes issues.
There are multiple algorithms for determining how DLM takes action, there are 15 minute bins and 24hr bins that collect the stats. It is as much to do with how frequent the disconnections are as well as the total number. In the main, a rule of thumb is to leave at least 30 mins between disconnection/reconnection so that the events don't happen in the same bin. The exact algorithms aren't published but Kitz is a good source of information.
Perhaps if you said what are you planning to do that you feel it might be an issue you would get some advice about whether or not it would be an issue and what steps to take to avoid it.