Recently, I bought a vintage Oyama (Taiwan) road frame from a local flea market when I was travelling around Java island.
To my surprise, it has a 70 mm BB shell English thread.
I've watched almost all videos related to BB especially ones from RJ The Bike Guy channel in youtube and read threads that talk about this sort of problem.
From what I could gather, the best option is to face the shell 1 mm each side and go with 68 mm BB.
My plan is to use a modern BB + crank (Shimano HT II) and keep it 7 speed.

I want to know if..
there's anyone here has had the same problem and gone with the same solution (face 1 mm each side) and use the same setup as I wanted (Hollowtech II BB).
Will it be alright? I mean, will there be any problem associated with the shell being machined when using the bike?
Or..
Is there better option?

Thank you.
J