I've mentioned this in other venues, multiple times, but have not seen any movement so trying here as well.

To aid with deranking prevention, make end of season rewards based on the amount of time you spend in a tier throughout the season, not where you finish. It will encourage people to continually play at their best level, rather than derank, because it will affect their rewards.
Example:
I spend my entire season jumping around in the 250-750 range. The last day I run into a series of strong opponents and finish season at 770.
[Today]
My rewards would be for the 751-1500 tier, even though I spent the majority of the season fighting at a higher level.
[Proposed]
My rewards would be for most time spent in a tier and be the 251-750 ones.

Jay spends most of the season, playing below his skill level in the 10ks. During the last weekend of the event, he makes a push and ends at rank 200.
[Today]
His rewards would be based on the final standing and would earn the 26-250 ones.
[Proposed]
His rewards would be for most time spent and would be for the 8001+ ones.