My experience for what it is worth.
2012 Tiger Roadie. 18,600miles from new. I have been riding 65 years (yes I am 81), Tutoro oiler fitted,any multigrade engine oil goes in during warmer weather, you have to thin it when the temperature falls. It does not like the winter, neither do I. I never clean my chain,I find that the crud flings off with the surplus oil. 25000 to 30000 can be had from an overlubed chain.
I have a Tutoro, what do you thin the oil with please.