Safety will drive my purchase more than anything, and if I find myself stalling frequently, I'll probably buy a Vortex to deal with the throttle & decel issues. To soften the blow, you can stick with the OEM exhaust and the Vortex should improve control. You can add the exhaust later.
Also, that price list is for all new parts. A quick check of eBay shows some used 450X parts, and I'll probably make my own heat shield before spending $53 on Honda's part. No way around the $700 price of the Vortex if you want the proven, do-it-all solution. You could try some of the other options to adjust the fueling and throttle response, but they still cost money, and don't fully address the problems. Frankly, I'd rather do it once, and do it right. A full ECU replacement fits that requirement.
On TT, there's been some discussion of an ECU piggyback from Bazazz:
https://bazzaz.net/product/honda-crf450l-2019/
Maybe it's great, but considering it's in the same price range as a Vortex, and the V is a known-good solution, I'd stick with it.