Just some copy-and-paste information from the forum and linked google doc announcements from the forum.
Official change:
"Hi all - we are officially loosening the multiple account limit - you are free to submit/stake on up to 10 accounts per user. With metamodel contribution, we want to strongly encourage users to try out new ideas. Full support for "one account - multiple models" at the website/api/compute level will be coming soon, and there will be a simple way to merge your multiple accounts. For now, go crazy and and start experimenting! "
Proposed change:
"Users are allowed 1 missing round in their window: if they have a missing round, it will be imputed with the stake-weighted mean of scores for that round."
For the proposed change about missing rounds, previously it was ok to miss 4 rounds without any significant downside.