Just a suggestion, but I modified my single tank adapter by putting a set of strap slots between the existing upper and lower slots. I dive single 80s and have had problems with boats that use the tank mounts that cradle the tank and are built assuming only one tank strap (e.g. Buddy Dive in Bonaire). This seems to work great and I've just used it every day for two weeks here in Bonaire with no problems. It is a little less secure in shore situations where you might get banged by the surge, but otherwise seems perfectly useful, a little lighter and faster to rig, plus fits those tank holders.
Any way, it seems like it would be trivial for Dive Rite to punch those extra slots and give divers the choice of one strap, two straps or even three (for ancilliary attachments).
Any way, it seems like it would be trivial for Dive Rite to punch those extra slots and give divers the choice of one strap, two straps or even three (for ancilliary attachments).