Just HYPOTHETICALLY, let's say that you were in Select and sold about X-many books a day, and then you left Select and suddenly started selling 1/10X per day, and HYPOTHETICALLY it was because the Amazon algorithms somehow favored Select participants...what would your reaction be?
A) "I'd better get back into Select!"
or
B) "I'd better double down on other outlets!"
But seriously, I really don't think there's a conspiracy against non-Select titles, that said, Select titles do have more chances for exposure (the library and the bonus bump of borrows).