the main goal of this tournament was to utilise the open tournament (which in my opinion is under-used)
If this is your only important goal, then I have no more proposals, set some funny/enjoyable settings and go.
But in that case you should not give the World Championship title to the tourney (of course you can :P).
I try to explain what I mean.
I do not know the Snooker system, but for example in the Tennis this tourney can be even a Grand Slam (the format good enough for it) namely the biggest tourney level. But the "World Championship system" in the tennis is not so simple. It is based on the ATP ranking system where count not only 1 Grand Slam but 4 (plus 8 ATP1000 and 6 best of other tournies = 18 tournaments). And finally the year end ATP World Tour Final. (you can read more about the system here:
https://en.wikipedia.org/wiki/2016_ATP_World_Tour_Finals)
As you can see, being Tennis World Champions is not to win one (even so important) tourney, it is much more.