I’m not able to import your flow JSON, could you try posting it surrounded by the ` character so that it gets interpreted as code text like this?
Using delay nodes set to rate limit may be one way to help, and if possible reducing the inject time would certainly help with overloading the queue. Is this running on an EPIC, RIO, or a different system? Using a control strategy would make running this type of application much easier.
Either way, I strongly recommend you look into using the dynamic groov node settings to do multiple read/writes with just one node. There’s another forum post to check out that should help you get started on how to approach that: Two ways to loop dynamic write objects for Opto nodes