This is technically undefined behavior as of 1.0.0, but it was recently brought to my attention that there is intent for 1.1.0 to make all dialogs close consistently upon pressing E.
I'd just like to point out that the version migration window that pops up when loading an older game save does not currently respond to either E or Enter in 1.0.0, (only Escape,) despite having a nice big green Confirm button (as described in the FFF). Please make sure that these (relatively obscure) migration dialogs, as well as other in-game error-handling type dialogs (such as mod/script related dialogs) all inherit the new behavior. (It would be nice if Enter worked too.)
[1.0.0][Reminder for 1.1.0] Migration dialog should respond to hotkeys
Re: [1.0.0][Reminder for 1.1.0] Migration dialog should respond to hotkeys
you have no access to 1.1.0 so doing a generic hints "make sure all dialogs work that way" is really rude and this topic should go into "ideas and suggestions" immediately. When the 1.1.0 will be out feel free to report which dialogs were missed. Other than that there is nothing wrong in 1.0.0. Not a bug.
Re: [1.0.0][Reminder for 1.1.0] Migration dialog should respond to hotkeys
Sorry, I thought it was weird (and unintended) that the migration dialogue in 1.0.0 doesn't respond directly to the regular hotkeys (E and Enter), and instead seems to store the keypresses(?) until the dialogue is closed (i.e. after clicking Confirm, I pop out of my car and my inventory opens).