The spreadsheet with people removed after 30 days was part of our old system, and they weren't actually removed, just paused (and reinstated after a couple of posts). That was because of a limitation in manual processing, and that limitation was removed with the release of our new system in December. We don't 'pause' anybody now. Pending vote value keeps growing until they post.

We don't think that early supporters took too much. It's intended to be a lifetime basic support, and early versus late shouldn't make a difference. In fact, when we deployed our new system, we calculated what everyone's value would have been with the new calculations and started everyone that had under-performed projections with catch-up balances.

The issues with the refund policy are around liquidity. Everything we receive from enrollments, author rewards, curation rewards, etc. is used to attain target SP levels that allow for a lifetime of sustainable support. That means we can't just refund everyone on demand - the STEEM is either locked up in SP or spent on delegations. 
Enrollment is a commitment, so the refund policy is intentionally strict. The best way to manage that is to factor in upvotes already received when considering what refund potentially could/should be delivered.

Your original enrollment is long enough ago that you qualify under the 'material change' clause for all of your enrollments before December 6, 2018. If you did not already attain 200% ROI over the duration of your enrollment, you could receive some refund of your enrollment amounts. In either case you might do better by finding somebody willing to pay you for units and request them to be transferred.