Wow! Why do you think 10 is fat too high?
Have you looked at Libre graphs from people without diabetes? They will spend less than 70% of their time between 4 and 6.5mmol/l. You are trying to achieve something which is unnatural and may lead to diabetes burnout.
I agree that spending long periods of time at 10 or above is not ideal but trying to restrict yourself to less than 30% of your time about 6.5 is crazy.
Take a look at people who have lived for 50, 60 and 70 years with Type 1. They spent the majority of their lives not being able to manage their BG even with a finger prick. Yet, they are still alive.
Twenty years ago, I was diagnosed with Type 1. I was finger pricking for the first 15 years so no idea about TIR.
My current TIR (using the recommended range) is around 80%, my HBA1c is consistently low 40s, I have no complications and intend to keep it that way. And when I talk about complications, I mean physical and mental complications whilst maintaining and very full and active life of which diabetes is a part but does not dictate conditions.