Agreed. The ANZAC frigates are the test platforms leading into the future frigate. I think the RAN should be congratulated for having the foresight to plan ahead in this manner.
I do hope the updated Navantia option is selected due to commonality with other ships in the fleet and also the fact industry is geared towards construction of the hull which should lead to less issues. Is the plan to stretch the Hobarts' hull?.
I can't remember who, but I asked this question and got a specific answer, there is no change to the Hobart hull length. Everything will have to fit on pretty much the same F-105 hull with the same dimensions.
Max hull displacement is 7400t. Considering where we are with the Anzacs, that is a pretty sizable increase. You can build a pretty acceptable frigate with 7,400t. Its unlikely to be overtly roomy, but we are also unlikely to hit up hard against limits like we did with the Anzacs.
If you want to put more stuff onto the Frigates, then you will have to specialise their duties and push things onto other platforms. I would certainly hope to make the Patrol ships flexible with containerised systems for UUV, UAV, mine clearing, survey, anti-piracy, humanitarian disaster, medical, SOF insertion, maybe even ASW.