Thanks Jeroen and all others who have answered :) I'll have a go at the ideas you suggested and see how far I get with it...
d) Tell Frank to not be so annoying, since the advantage (a bit less build-deps needed during build time, but no differences in the resulting .debs) does not outweight the possible issues you're introducing now or in the future by making a mistake here, nor the excessive amount of time it takes doing this right... ;-)
That suggestion has particular appeal ;) But I guess it would break the "rules" for NM <sigh>. Better just go do what my AM says to do...
Thanks again, Helen.