I couldn't find anything like what you're asking for after a quick Google search. Just my 2 cents, but I think this is a case where you can't have your cake and eat it too. Some noise cancelling headsets allow you to mute the NC circuit to hear if someone is talking to you, but I know that isn't what you're looking for. If you really want to be able to hear background noise, it doesn't seem like ciems are the right choice for you. Part of why a high-end ciem such as the K10 excels is that you can hear some subtle details in recordings due to the isolation it provides. I wonder if the universal K10 would better meet your intended usage, since you can somewhat adjust the isolation by experimenting with different tips. Hopefully someone else will know of such a product, though.
The UMmodTF10 I have now has good isolation and good seal but I can still hear sounds on the outside somehow. I intend to order the K10 soon, but it didn't occur to me that the isolation could be actually greater than what I now have. Hmmm. Is the isolation on the K10 that complete? Really?