I do not see how this makes a difference, Tobias.
A few days after the zygote is formed, inside or outside the womb, the gandhabba enters. The gatis of the donor or donors are there in the spermatozoa and in the ovum in either case.
I of course stand to be corrected.
P.S It is of more concern what the state of a frozen EMBRYO is , that is, once the gandhabba has entered. Will the ‘mind-component’, as you have it, that is, the gandhabba ,frozen for all that time?
Metta