Lua Script uses only Write commands and Cannot Scale in a Redis Cluster
https://github.com/animir/node-rate-limiter-flexible/blob/d4e26c0748e9213b5646694f8a3d46db8ba56824/lib/RateLimiterRedis.js#L5

When i went through the Lua script above. I noticed that it doesnot have any Read commands.

It works based on the response of the write command.
`local consumed = redis.call('incrby', KEYS[1], ARGV[1]) \`

In a Redis Cluster, normally read commands go to replica nodes and we would increase the replica nodes to scale to tackle load, 

But here since we only have write commands we wont be able to horizontally scale (write commands are handled by one primary node). Wont this cause problems in the long run by introducing a bottle neck ? 

Steps to reproduce : 
1. I checked a aws elastic cache redis cluster for the get commands metric and its 0.