Getting Row Subtotal to 'turn back on'

Good morning experts!

I've built a hideously complicated DAX measure and it's not working. The intent of this measure is to perform a simple SUM() calculation for a handful of specified projects, and 'turn off' the other values that havent been specified. To do this, I built two virtual tables:

Var projectinlist = 
{"D", "E", "F", "G"}

Var projectoutlist = 
Calculatetable(
Values(MSTR_Project[ProjectID])
Filter(
MSTR_Project,
Not (MSTR_Project[ProjectID] in projectinlist
)
)

The next lines accurately calculate the sum ('calcsum' below), but the final variable is where I get into trouble. In order to 'turn off' all of the projects in projectoutlist, I do the following:

Var result =
Switch(True(),