TL;DR: How to choose the width of the confidence intervals one reports?

I am working on a paper on statistical technological forecasting.

Our model produces confidence intervals for the date when a particular milestone will be achieved. I am now thinking about how to report the results.

One line of reasoning is that you want the results to be as informative as you can, so we would report 90% confidence intervals.

Another one is that you dont want to overstate your results, specially on a domain such as the one I am working on where model error could be as high as 1/3 of the models. So your confidence interval should be commesurate with the expected base rate of model error (eg 70% confidence intervals in this case).

I think I am not framing this problem correctly, so any thoughts would be appreciated.

It's good to know that this a extended practice (do you have handy examples to see how others approach this issue?)

However to clarify my question is not whether those should be distinguished, but rather what should be the the confidence interval I should be reporting, given we are making the distinction between model predection and model error.