They use mixer, definitely no auto switching. Sequential usually got MAP sensor to detect pressure in gas regulator, auto switching to petrol when gas pressure low. Sounds like the same, but in mixer, switching requires 'draining' of gas/petrol from manifold/fuel line, otherwise it won't be smooth. In sequential, all these switching is immediate and can be unnoticeable.

If you go early, 1 day kao tim. I went in the noon time, already tuning at 3PM+. Very fast.

Lol apasal tak buka?

~4k.

Carbon fibre tank, just tank alone, ~7k i think.

Full carbon fibre tank is exotic, only used by supercars or performance cars. Not for me or you.

Use long nose pliar

3.75. You will be charged 4L

They don't use bottle. Nothing to return.

Don't know if it differs, I went to big service center, they don't use bottles. They are supplied in drums