Performance - Multiple measures and variables

This is not your basic "should I use a variable or measure" question. 🙂 I need to optimize variables and measures.

I want to produce a measure that returns number of events this week and how that changed from last week. This can get really complex since "number of events" can mean "count this type of event, add it to that type of event, and filter this third type before adding it." I'm trying to optimize performance for that process to get me to my single final output.

I'm using some of the intermediate measures elsewhere on the page. For instance, I have a card with Opened Last 7 Days so I need a measure for that anyway, but then I also need to include it in this larger calc.

So the question is: Should I create one single measure with every calculation included as variables even if it duplicates measures that already exist, or create all individual measures (which include duplicate calcs) and refer to them in the final measure? 

Option A:

Opened Last 7 Days = 
    var _MaxDate = MAX(Dates[Date])
    var _Last7Days = _MaxDate - 7
    
    var _Formula = 
        CALCULATE(
            COUNT([EventID]),
            [OpenDate] >= _Last7Days)

Closed Last 7 Days = 
    var _MaxDate = MAX(Dates[Date])
    var _Last7Days = _MaxDate - 7
    
    var _Formula = 
        CALCULATE(
            COUNT([EventID]),
            [CloseDate] >= _Last7Days)

Abandoned Last 7 Days = 
    var _MaxDate = MAX(Dates[Date])
    var _Last7Days = _MaxDate - 7
    
    var _Formula = 
        CALCULATE(
            COUNT([EventID]),
            [OpenDate] >= _Last7Days,
            [Status] = "Abandoned")

Total Changes Last 7 Days = 
    [Opened Last 7 Days] + [Closed Last 7 Days] + [Abandoned Last 7 Days]

Option B:

   var _MaxDate = MAX(Dates[Date])
   var _Last7Days = _MaxDate - 7

   var _OpenedLast7Days = 
        CALCULATE(
            COUNT([EventID]),
            [OpenDate] >= _Last7Days)

   var _ClosedLast7Days = 
        CALCULATE(
            COUNT([EventID]),
            [CloseDate] >= _Last7Days)

   var _AbandonedLast7Days = 
        CALCULATE(
            COUNT([EventID]),
            [OpenDate] >= _Last7Days,
            [Status] = "Abandoned")

Total Changes Last 7 Days = 
    _OpenedLast7Days + _ClosedLast7Days + _AbandonedLast7Days

These are WAY simplified - my actual calcs are much more complex and there are a lot more of them, which is why I need to know how and in what order PBI processes measures and variables. Is it faster/more efficient to have everything defined in one single measure, or is the performance difference close enough and I can keep them all in separate measures? Also, once PBI has calculated a measure once in one visual, does it have to re-process that for another measure or is it effectively cached? How does the processing hierarchy work - some of my intermediate measures refer to other measures, so there can be several levels it has to go through - does that impact performance?

Thank you for your help!