I suggest trying the 4430 as it is then for a while with your new networks.

If you lust for further sonic enhancement the road ahead splits two ways:

1. Install a Radian one inch compression driver with a BE Diaphragm.

2. Add the JBL 2123H 10 inch mid driver making it a very nice 3 way system (which I have used myself with great success)

I do not recommend adding a UHF driver to supplement the bi radial horn.

After that its another loudspeaker design .
https://klappav.com.au/collections/jbl?page=1