Scaling Logstash: Redis queue - channels or list?

We are in the process of setting up new ELK stack. The idea is to have:

N nodes --> 2Logstash Shippers --> Redis (Master/Slave) --> 2 Logstash Indexers --> ES cluster --> Kibana

Only problem we have right now is the configuration/usage of Redis. Should we go for Redis lists or channels?
Can we define 2 Redis input plugins on the logstash indexers of the data_type pattern.channel ?? Or should we stay with 1 list (RPUSH/BLPOP) configuration?

I like the idea of having multiple channels to have better management. But does it work with multiple indexers?

Kind regards,

Stefaan