Dual sim yes, DAC yes, wireless charging no (already asked and answered, please search before asking question next time).
I am not sure why you had the impression the CS is bad/service centre is terrible. I wouldn't say they are terrible/bad, just too many devices to fix and lack of manpower to go through them, hence quite slow.
E.g., I dropped my G6 at SC yesterday morning. I just went there this morning, but nothing was done yet, so asked them to return my device, since my seller has agreed to exchange 1-1 (just called me 6pm ytd).
Slow maybe, but bad, I don't think so. the CS was polite for my case.
Thanks bro, noted on the search part.
One more thing, does G6 come with UFS2.0/2.1 for their storage? Tried to search this thread but couldn't find the answer.

