Advice on buying a used Gen 4

Howdy y'all!

Long time reader and first time poster. First, a big thank you to all of you! This forum has helped me DIY many projects on my first prius (Gen 2, 2007 base) since I bought it 6 years ago.

I'm planning to upgrade to a used Gen 4 for comfort and reliability after multple large projects on my 07 causing stress and demanding my dad and I's weekends (replacing rack and pinion, tie rod ends, inverter cooler pump 3 times, fuel door cable, clock spring, parking brake, and currently fixing the hybrid battery).

That being said, I want to continue to be able to DIY these kinds of projects in the future. I would appreciate y'all's insights on these questions and anything else you think I should know! (I have already read the last few pages of the newbie thread)

1. Is the Gen 4 easier or more difficult to work on compared to the Gen 2?
   
2. At what mileage would you disregard a used Gen 4?
   
   1. For example, I'm seeing a 2019 for $13k but it has 190k miles on it!
3. What kind of service history would you require for a high mileage Gen 4?

I have a Veepeak OBD scanner and the Car Scanner & Dr.Prius apps so I plan to run those tests before making the purchase. Also planning to hire an independent mechanic to check cars out of state if they're worth the trouble.