I may have to try out my old basic level early access version and see if there's anything new to try out,
Do it. I'm sure there's quite a bit of new stuff for you to play around with. Latest Junior build is 698.
I had a quick rummage around earlier and was impressed with the new intro and UI changes, managed to find a couple of new cars I can access too but I only had a controller hooked up so didn't spend any time driving (it doesn't play well on a cheap knockoff Xbox controller for me).
I still find their whole menu system confusing as fuck though, especially since half of it is dummy stuff that isn't available yet like Career mode. I'd sooner it just say "Coming soon!" instead of leading you on a merry dance through some dummy pages of how it may look once complete.
But other than that minor grumble it is definitely looking very good!