Delay from variable in trigger

I have a variable in a rule, but there does not seem that I can pick that variable in delay ( And stays off for:) .. I can only use the constant for the delay..
is there any workaround for this ?

I could understand if a local variable would not be selectable in the triggers section, and to a lesser extent hub variables (given they can change at any time). As a work around you could trigger based on the device turning off and then include a wait as the first action that uses the variable, which can be cancellable. Technically setting of the variable would need to be the first action, if the variable is local to the rule.