GF - that sounds like the guts of the matter
V1/VR - the OP doesn't give us much to go on. However, I presume he/she is looking at the effect of V1/VR on whether OEI or AEO conditions are limiting. If so, then consider the two extreme cases for either 4 or 2 motor jobs ..
(a) V1=VR where we would expect the minimum difference in TOD between the OEI and AEO cases. In this situation, the AEO case is most likely to be the limiting case - not guaranteed to be so but most likely compared to any other V1/VR.
(b) V1/VR at the minimum value, whatever that might be for a particular aeroplane. This results in the greatest speed delta to be achieved during OEI operation to get to VR .. as well as the final flare to screen contributing. In this situation, the TOD will most likely be OEI limited.