I suspect the main differences are due to the slightly differing inheritance patterns between the two; the pod parent actually contributes more, including cellular organelles such as mitochondria, chloroplasts and other
plastids. The pollen parent only hands across its half (assuming both plants are 2N) of the nuclear DNA.
Obviously, those organelles (some of which have their own DNA) will influence the plant - and the overall environment of the inherited DNA from both parents.
The example in humans is that the mother hands over the mitochondria in the egg (hence tracking the female line through mitochondrial lineages); on exceptionally rare occasions, "male" mitochondria may be contributed from the sperm, but these are normally left outside the egg. The sperm normally only hands over half the father's genetic material, including an X or Y chromosome.
I am not sure how you would know which is the "better" direction without a "try it and see" approach beyond the broadest patterns.
One rule of thumb that is used is if one plant is rather weak and the other well established, the weak plant would be used as the pollen parent and the other as the seed parent, as it takes a lot more energy to mature seed that produce some pollen (indeed, once flowered, the pollen is obviously already made).
---------- Post added at 09:50 PM ---------- Previous post was at 09:35 PM ----------
Incidentally, considering this, I find it quite suprising the reciprocal crosses share grex names, and I would certainly think that which way round a particular batch of a grex was formed and which version used in subsequent breeding would be potentially useful information (much like knowing which clone of which parent was used).
Capsule vs pollen parent
Hybrid Mode
