My read on this - no point making any decision on retail++ status... it is irrelevant for stocks. Advance and Premier customers pay the same commissions and see the same charges on stock holdings.
For the record - am perfectly happy with HSBC HK + DBS HK for access to HK/US/UK/SG markets.
In my experiments with HSBC / DBS / SAXO / IB - I found my current solution described above as the most painless and effective for dividend income.
HSBC Expat seems to have marginally better FX rates - I had originally looked at this for buying UK ETFs via InvestDirect, but did not proceed as DBS worked for me, continues to work. They also have better GBP fixed deposit rates (for new funds only) - may be for HKD/USD too... have not checked. It could serve as a good vehicle to keep your cash if you are concerned about capital controls specific to HK.
The higher transaction cost is not that big an issue, as the round trip cost is factored into the purchase price... and becomes irrelevant when you look at your total return.
(And randomly - specific to stocks - other than transfers, we've not had any human or individual contact with any of these banks in say the last six months.)