Sounds super legit
There is a storefront on the floor above ground inside of the world wide plaza. Has the red Smartone colouring. The big shops are reselling CSL on the outside edge of the building. Took a photo of my ID before handing over SIM card. They offered to set it up for me on the phone. Supposedly there is $98 of value for HKD$50 cash. Got another $50 voucher and that should cover a month.
https://www.barkadahansasmartone.com...h/service.html
You can port in to keep your number, but it may take 4 days to process.
SoSIM has a FDW HKID holder offer as well, a bit cheaper than the sosim deal. But not really useful for monthly data replacement.
https://www.sosimhk.com/en/offer/mig...r-special.html
ymmv