They’d essentially have to do at least two evictions per week for the entire series to feel somewhat complete and even then at 4 weeks we’d have virtually no time to get to know the HM’s.
Also hoping they expand for future series isn’t ideal… I can almost guarantee they’ll never get the series anywhere near where it should be. Decent ratings will pretty much confirm whatever misguided belief 10 have about the series that led to this decision. Bad ratings will simply confirm the idea that BB is a dead format in Australia without looking at why the series actually failed.
Whilst I'd prefer a half-week cycle with nominations and evictions in each I think a double eviction each week is probably neater, and more cost effective if they're having a live audience. Perhaps if they keep it to 12 HMs rather than have the 16 BBUK has it's not so bad doing weekly evictions. If it's 6 weeks you can have 4 singles and a double over the first 5 weeks then in the final weekend (which I imagine would be over Sunday/Monday) have a double on the Sunday (as a result of nominations), then 4 in the final.