Ability to Adjust Carrier Generated Estimated Delivery Dates in Checkout? Has anyone discovered how to adjust or change carrier delivery estimates that are auto generated and displayed in checkout by the carrier? We are having issues with our USPS integration not properly displaying estimated delivery dates in checkout because we are unable to factor in our in house processing time that is dynamic and can change day to day.

Screenshot of what I am talking about above.
Any responses are welcome. Cross posted this to Shopify Functions as well, mods feel free to remove this one if needed.
I should also note I after quite a bit of research and time with Shopify Support there appears to be no built in way to dynamically adjust these.
However, I refuse to be think we are the only store with this issue. So even hacky answers would be great.
I am in the same predicament. Did you figure this out? We need to add our production time and want to use the carrier based costs, but there must be some way to intercept the API from the carrier to add x days to the date that comes back from the carrier.
I found an app that will do this:
Advanced Shipping Rules app in Product Groups>By Price>Zone: Domestic>Processing Schedule>Processing Time