I’m not an authority on this by any means. Many others have more direct, hands-on experience and would likely be (much) better informed. That being said, we need more cowboys to test the platform, push the aftermarket to provide more options, etc. so thank you for your service.
For reference, as additional perspective, I have a very low mileage 2020 HE LC. If I spent the money to do a supercharger correctly on this five year old used LC, given current market value, there would be minimal financial buffer vs a new LX600. I see multiple new LX600s for sale for under $105K and that’s before any negotiations. Could probably still find a buyer for 2020 at $80-85K is my guess.
In my case then the financial argument doesn’t matter as much. The new car warranty on the LX600 would easily be worth the $5-10K delta. The minute the reliability or durability of the 200 series comes into question, the platform, to me, no longer makes sense. If I needed to replace blown gaskets or cracked pistons on a car that still barely gets to 60mph in the 5 second range, I would have to have a serious thought about continuing to invest… a Honda Accord 2.0T has the same or better 0-60 for context and would still make a great daily driver.
After some initial stumbling on the engine issues of for Toyota/Lexus, I am willing to bet that new model year LX600s will be very robust. You’re absolutely right that the roll-out of the new engine and platforms has been far from flawless. But long term Toyota/Lexus seems to have a great understanding of hybrid tech, as good as any company globally, and they’ve demonstrated again and again that their 4x4s are some of the longest lived of any brand. This makes me feel good about the new LX700 and the current LX600.
All that being said, the specific use case is the most important thing to consider. If you stay within 50-100 miles of your home, don’t tow, don’t offroad, and want a quick SUV, there are plenty of options that probably make more sense. The slowest BMW X5 from five years ago would still be faster to 60mph than a supercharged 200 and could still be under a CPO warranty. For $60Kish you can get a X5 with a V8, under CPO warranty that will do 0-60 in the mid 4 second range and, critically, has the suspension, brakes, tires, drivetrain, etc to safely handle that speed and power.
Keep pushing the limit of the platform for the rest of us, but don’t kid yourself on what you have. That’s the fastest way to end up frustrated, and it accelerates the likelihood of moving on to a new platform entirely, at least from my experience. Appreciate the 200 for what it is — a very well made, very reliable, exceedingly comfortable SUV for getting you there AND back.
Good luck!