I think you posted to the wrong version of the rule. This is the OH 3.x version of the rule template and it does not support hysteresis at all nor does it support overriding properties on a per-Item basis through Item metadata. I think you are referring to the 4.x version of the rule template.
My answers below are for the 4.x template.
Yes, all rule template properties can be set on a per-Item basis with the Item metadata.
This sort of thing is exactly why I added the per Item metadata option. Sometimes you want almost everything to work the same but there’s always that one outlier that is slightly different.
What the rule does is have the default properties hard coded when the rule gets instantiated (variables at the top of the script). Then when an event happens that metadata for that Item is pulled and overwrites the defaults to create an Object I call record
. This record
is used to process the event for that Item.