Multiple Condition IF using switch true

Anonymous This looks like a reasonable interpretation for how to handle multiple values. However, the naked P1, P2 column references will probably still cause problems.

This is what my version would look like using this logic:

Migration Status =
VAR RB  = VALUES ( 'Consolidated Sheet'[RB] )
VAR GTP = VALUES ( 'Consolidated Sheet'[GTP] )
VAR GBS = VALUES ( 'Consolidated Sheet'[GBS] )
VAR ITL = VALUES ( 'Consolidated Sheet'[ITL - EXP non premium - EITL - Non premium - Binder Price Plan] )
VAR EXP_B  = VALUES ( 'Consolidated Sheet'[EXP - Binder Price Plan] )
VAR EITL   = VALUES ( 'Consolidated Sheet'[EITL - Binder Price Plan] )
VAR P1_Max = SELECTEDVALUE ( 'IRR Retina'[P1 Max - Binder Price Plan] )
VAR P2_Max = SELECTEDVALUE ( 'IRR Retina'[P2 Max - Binder Price Plan] )
RETURN
	IF (
		ISBLANK ( P1_Max ) || ISBLANK ( P2_Max ),
    	BLANK (),
    	SWITCH (
        	TRUE (),
        	P1_Max = P2_Max,                                           "Retained",
        	P1_Max = EXP_B && P2_Max IN UNION ( EITL, ITL, GTP, GBS ), "Downgrade",
        	P1_Max = EITL  && P2_Max IN UNION ( ITL, GTP, GBS ),       "Downgrade",
        	P1_Max = ITL   && P2_Max IN UNION ( GTP, GBS ),            "Downgrade",
       		P1_Max = EXP_B && P2_Max = RB,                             "Upgrade",
        	P1_Max = EITL  && P2_Max IN UNION ( RB, EXP_B ),           "Upgrade",
        	P1_Max = ITL   && P2_Max IN UNION ( RB, EXP_B, EITL ),     "Upgrade",
    	    "Cancelled"
		)
	)

In this, P1_Max and P2_Max cannot have multiple values but the rest of the variables can.