Ensure fast node response when incoming traffic ramps up sharply

### Problem

See https://github.com/hashgraph/hedera-testing/issues/404 for context.
This is an umbrella ticket to cover efforts in the entire stack from client test code to Hedera application.
The target is to ensure the network is stable against sharp increases in incoming HAPI calls and can ramp up transaction processing quickly.

### Solution

Analyze current node/network behavior. Propose solutions where needed.

### Alternatives

_No response_