And, on a final point, I don"t know about the additional venues that you linked to but it"s an APAT requirement that the venues are fully and appropriately licensed.
Another factor to throw in.
even if a venue is licenced etc we need to have comfort that they can manage everything with us, efficiently. From capacity, to food, to TD, to dealers, to cashier to disabled access, parking etc
In essence, a venue needs to be an experienced provider of the services needed to put on poker events for third parties.
We can go to new places, but I don"t particularly want to take huge risks with APAT events and risk the player experience . In general less risk = the known providers. Although experience is no guarantee of avoiding cock ups (no names mentioned), it"s generally our policy to use established venues