There is more lead in 97. The lead is for the grease purpose of the engine. So generally more engine power needs better grease capacity from the petrol = higher octane. But nowadays there are other chemicals to add in order to obtain the same grease capacity of the petrol. You can always use higher octane then recommended but not lower. Just use what the manual states. So there is not more "power" or something like that in higher octane petrol. The engine will not become more strong.
Most countries in the world have the regulation to have the engine running when the car is standing still (idling) max 1 minute. Not because of the smell but because of the air pollution that we have already. If it is to warm in the car for you then go out of the car!
So everytime you change car or motorcycle or renew the passport or open a new bank account, there must be made a new Thai will? That sounds strange.. sounds like a good business for the lawyers.
Otherwise here is a good webpage were you can buy activation keys very cheap and full legit. The only is there is no support from Microsoft for this keys. But who needs that?
https://pixelcodes.com/
Just buy a windows 10 key and and an Office key and you are fine. Or uninstall Office so you will get rid of the annoying message. You said you are not using Office anyway so...
Sometimes it is an underlaying cause. My wife who is a hairdresser helped a neighbor by telling her that she must take care of her diabetes and also sleeping habits and that helped. She dont have thin hair anymore. It look normal. And she feels better too from taking good care of the diabetes.
I did a lot or research about 15 years ago and ended up with Prins. That time it was the best brand. Also used in Europe a lot. Don´t believe in what they are saying here about burning walves etc etc. If that shoult happen then there is something wrong with the equipment. And not forget to drive with Benzine every fourth or fifth tank in order to grease the engine. And preferable with the highest octane you can find. Higher octane means more lead and that means better grease. But your FB page looks good as well. Be sure they are mounting an European equipment. They have probably different brands same as the Prins garage had that time. Better pay more and get good quality. One more thing. You must change the filter as saying in the manual. Many thais try to save money on that and in the end they get problem. That is not were you want to save money. Good luck!
And much better for the environmental. Much cleaner than benzine or diesel. I can recommend the brand Prins from Nedherland. More expensive but good quality. Otherwise there are systems from Italy, Hungary, India etc..
https://prinsthailand.com/