Too much latency/pending messages

[ludovit-ubrezi]

Hello,
with are using Asynq with e.g. 4.5M messages in system.

Most of messages(90%) has delay between 1-5 minutes and 10% could be up to 24 hours.

We got 14 servers with each 20 workers (screenshot below)
Queues are lagging like a lot (pending messages screenshot below) we are using Redis scaled up to heaven.
Also we pushing messages into NATS so its simple get message push it, which can take pounding(50k messages in 1 second or 50k op/s) as we push into it from each side and its properly scaled up.

Could even Asynq handle this pressure? Also why are not all workers in usage when there so much pending?
Its possible to provide some example how to setup it (we done it by documentation) but i could be we missed something because of that 1/20 workers?