How to improve performance of MySQL group replication?

In MySQL 5.7, there is a new feature called Group replication used for fault tolerant system.

Group Replication Doc

I implemented the group replication with 1 master and 3 slaves and it working fine. But i feel it little slow. Slow means query taking time in execution on master. It may be because of master waits for acknowledgement from slave or time in certification acceptance etc.

I know it may be broad question but if you guide some parameters related to group replication to improve the performance then it will be helpful.

Thanks