Originally posted by howieb101 You don't need to keep acquiring Cactus V6 II's for each flash.
That's true if using a single V6II as an HSS enable works with the hardware available.
Originally posted by howieb101 The Cactus V6 II acts as a HSS enabler only and the triggering is all from the Godox trigger.
That's one approach and certainly the most cost-effective.
However, if the trigger one uses doesn't work on top of a V6II or one doesn't want two triggers on the camera at the same time then using a V6II receiver connected to the off-camera flash with a sync-cable is also a viable approach. I do this myself (using my old V5 triggers) because my Jinbei remote has a strange upside-down design for camera mounting and I'd have to move it manually from "power adjustment" to "triggering" mode and back again all the time. So I just use my V5's for triggering and still remote-control the strobe's power levels with the Jinbei remote (which I leave in a pocket or on a table nearby). In my case this clearly makes more sense then attempting trigger stacking.
Originally posted by howieb101 It seems Cactus like to advise to buy additional Cactus V6 II's when they are actually not required. Smart move by them but better to save your hard earnt $$$.
In my view you are misrepresenting and I'd say it wouldn't be "smart" at all by Cactus to do this. A company pushing their products when they are not needed would be exhibiting reprehensible behaviour, AFAIC. All I've seen Cactus do is to state that they don't support trigger stacking and that the only officially supported way of using otherwise incompatible third-party equipment is to use a Cactus receiver at each light.
One can construe "not supporting trigger stacking" as a scheme to foil attempts at using a single V6II as an "HSS adapter" in order to sell more receivers. However, in my view the far more economical explanation is that some third-party triggers don't do a great job of emulating a speedlight. Given that some third-party triggers work on the V6II, it seems obvious to me that at least part of the "blame" sits with the products that don't work on the V6II. Obviously Cactus could try and make their V6II compatible with triggers that don't manage to emulate a speedlight in a manner that is compatible with the V6II but I think that's a bit much to ask for. This would require development costs for no gain to Cactus as they are not selling the V6II as an "HSS adapter".
Given Cactus' history with numerous free improvements via firmware updates (this started with the V6, continued with the V6II, and culminated in upgrading the V6II into a full-blown "P-TTL via radio" device), I think it is strange to view Cactus as a company that attempts to unrighteously obtain money from unsuspecting customers.