Thanks for reaching out to Q&A.
Yes. Your understanding is correct. You can increase the timeout value by changing "functionTimeout" value in host.json file. Please refer to this article for reference :
https://zcusa.951200.xyz/en-us/azure/azure-functions/functions-host-json#functiontimeout
As mentioned in your question, for HTTP triggers, there is a 230 seconds response timeout that is set at the load balancer which cannot be changed. I have explained clearly Function architecture and why the 230 seconds timeout cannot be changed in the below thread. I would suggest you to go through it.
https://zcusa.951200.xyz/en-us/answers/questions/758823/httptrigger-response-timeout.html
I hope this helps!
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