I'm curious to hear from an actual Sponsor if this is a hassle or not, and just enlightenment on how the Sponsorship process played out. And hopefully, stories of success.

As stated here on immd.gov.hk , an Investment Visa Sponsor can be any "bona fide" HK resident over 18 & "acquainted with the applicant" who agrees to "assume responsibility for the applicant/investor's repatriation to place of domicile" should the limit of stay expire and "the applicant fails to leave HK." ... a pretty loose set of parameters...