If you decide to delete the Aux pump, replace it with a 90˚ brass elbow. The vanes in the pump block coolant flow to an extent, with the pump removed and a 90˚ elbow inserted in its place, my SDL heats nearly as good as with the Aux pump running. Certainly no issue making the cabin too hot to tolerate.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)