Great that you're loving your (my former!) 425. They are remarkably good basses for the money!
What is about getting a 425 that makes folk want to jump straight to the top end of the Yammy range?! @dave_bass5 bought another 425 off me (yes, ok, I seem to be turning into a used 425 salesman 😁) and got himself a P34 before I could say "TI Flats"!
But I'm not sure I see the jump from 425 straight to a BB2025 as being an 'obvious' one. Certainly not something I personally would rush into doing, because I suspect you could get to 95% of the 'sound' of a 2025 with a BB1025 for 40% of the cost; they are identical in terms of pups, woods, EQ and construction. The 'additional' that a 2025 brings to the party is (i) being MIJ and (ii) it has had two specialist sonic treatments. Some may think that warrants charging 3 times the price, but I'm not in that camp and I've certainly been very happy indeed with my 1025.
The modern day take on the 2025, with lighter tuners, is the P35 and as that is a in-production model you could give one a spin and see what you think. The P35 is given one of the two sonic treatments that the 2025 had, but has an updated set of pups and VVT controls rather than selector switch. It's pretty close in sound to the 1025, but not identical and my guess is that the 1025 is going to be the closest tonally and in feel to the 2025.