Looking at the MDC times for Efke 25 pushed one stop could be between 10 and 12 mins in Xtol 1+1 It seems to depend on whether you look at Efke 25 or Efke 50. and whether you regard the 25 as the equivalent of Efke 50.

A compromise might be 11 mins in Xtol 1+1 if you cannot find anyone who has developed Efke 25 in Xtol or HC110 pushed two or is that one stop?

HC110 and your experience of it being a one stop push with your reliable figure for it at 9 mins and two mins for a stop suggests 11 mins as well

A jump of nearly 45% for a one stop push sounds a lot