- group1 includes almost all wikis which aren't Wikipedias, including two of our largest and most complex wikis, Wikidata and Commons.
- Each time we bump the train to group1, some of the fallout happens at a scale that is unfeasible to manage and hinders investigation.
- Problems most often hit Wikidata, which is exceptionally complex and has a number of unique features.
- The train rolling late on Wednesday to Wikidata means we have to rush to try to fix it.
- Split group1 into group0b for Wikidata, group1a for most wikis, and group1b for Commons.
- Try to roll out the Wikidata change on Tuesdays during European hours so that the Wikidata team are around, after the main group0 deployment
- Roll out the group1s on Wednesday, maybe 15 minutes apart, to allow things to settle between deployments.