The 10% increased planet size needs to be retroactively applied to any planets colonized BEFORE the account switched to the Discoverer class. As it is now, high ranking players with several planets do not get to take advantage of this bonus unless they decide to abandon and recolonize. That would be extremely wasteful, especially for players who colonized mid slot planets for the size and then paid for Dark Matter to relocate them to slot 15 for increased deuterium production.
As it is now, Discoverer loses one of the class benefits simply because colonies are already established. None of the other classes have this issue. While some may say this isn't a big deal, it would be the equivalent of about 230 extra fields on my main account. That's an entire extra set of Astrophysics, which is the equivalent of 457kk metal, 913kk crystal, 457kk deuterium and 8 weeks of research time for me, and would be even more for people with larger accounts.
This change would actually allow the company to profit more off the class switching as there will be those who switch to Discoverer for the size boost, and then back to their original class.