Thank you for the suggestions, dump247. I initially considered implementing the debug view types for ReadOnlyDictionary, but had to work on some other things and didn't want to spend too much time on the class. My mitigating rationale to leaving it as-is, is that ReadOnlyDictionary contains only one field, which will render appropriately in the debugger when expanded.
Nevertheless, this will add completeness to the type and I will surely implement it in the future.