I’m not sure how you got a support for expansion theory from these accounts because the parables are ironic parodies, the first two describing “expansions” that normally wouldn’t occur. The last illustration you point to has nothing to do with expansion at all, not even shape.
Matthew 13.31 is a parody of Ezekiel 17.23; 31.5 and Daniel 4.7-9, 17-19. It’s an ironic comment because mustard seeds are tiny but can sometimes grow into trees due to their destructive nature of killing all other vegetation in their vicinity and sucking all the nutrients from the surrounding area that would keep the other vegetation alive. (Compare Daniel 2.44.) Because of this Jewish law during the Second Temple era regulated the planting of mustard to avoid the results seen in this parable from ever happening.
Verse 33 is also a parable of irony because it is an exaggeration. Though a leavening agent, yeast has its limits. You have to have enough for your job or it won’t work. The woman in the parable is working with “three measures” of flour, which is approximately 60 lbs. The result is unexpected because the dough should not rise under these circumstances if the woman used the small amount of yeast most households had on hand. If you applied the Baker’s percentage (which tells us how much yeast is required to make that much flour rise), that would require 2.4 lbs of yeast. That’s a monstrous amount, and likely not the idea Jesus had in mind due to the genre of the illustration. Jesus was contrasting this parable with the mustard seed one, tiny beginnings causing great expansion. 2.4 lbs is not small. Scientifically this parable is impossible with normal household amounts people even keep on hand today, and Jewish men and women who baked in Jesus’ day would have recognized this absurdity--which is the point of irony.
Verse 45 is using an old Jewish illustration common to Hebrew culture which relates pearls to piety and study of Torah, such as appears in the Acts of Peter 20; Avot of Rabbi Natan 18A; and Peskita Rabbati 23.6. The shape of the pearl is not the issue in Jewish culture. It is the value of such a rare find, like that of a precious stone such as a ruby or emerald. To see value in the shape would be introducing into the reading of a text an anachronism foreign to the writer and audience that commonly used the item with a different definition.
In the end, I am sure you have answers for these points I raised developed from those who validated your conclusions (no scientific theory can be called a “theory” without independent confirmation from disinterested parties according to the method).
While I don’t believe in Jesus Christ, as a Jewish philologist I am quite familiar with the parables of Jesus and the different type of parable genres used in ancient rabbinical and early Christian cultures. The “parables” of Jesus are actually “mashal,” a literary form which included not only irony like the first two parables discussed above, but allegories, axioms, proverbs, and similitudes. Does the type of parable (genre) affect how they relate to your conclusions? Do they figure in at all?
And how did you get a theory of expansion from the first two ironic parables, since they are discussing things that generally never if ever happened?