This referenda increases the parachain validator set size from 300 to 400 and the maximum backing group size from 3 to 4. As a result the total number of cores remains 100 (coretime_cores: 56 and 44 inactive)

The reasons for also changing the backing group size are:

• https://kusama.polkassembly.io/referenda/294 changes to a backing group of size 3 has shown to increase parachain block times
• keeping the same number of total cores such that all 100 backing groups get rewards given the session is 1 hour and group rotations happen every 1 minute

For more details check out: https://forum.polkadot.network/t/update-parachain-validator-set-size-increase-on-kusama/8218

Whitelist: https://kusama.subsquare.io/fellowship/referenda/80