Nice update, more seat time before any further modifications is probably a smart call.
I found with 3" of poke on my first splitter that it made such a difference i was actually slower for having to correct the rear the whole time. So youve probably done yourself a favour on track aswell by having less.
Also means you can share the experience with us.
Nice build so far mate! Interested to see how the splitter improves performance as I'm looking at something like this.