You mention two weeks unstructured training everyday - might have better to have one day with no training. A lack of recovery days could be an issue.
You won’t really need base again, but training in between a races is always a question mark. If you’re happy with your bike performance and are struggling to build a lower intensity or speciality may work better or as you suggested yourself just maintenance activity.
4:30 is quite a target, how far off that were you in June?