May I be allowed a couple of observations that might help this thread along?
First, the RN's 'through deck cruisers' (the 'Invincible' class) were most definitely not designed to go upthreat and 'hack the shad'. (That task appeared in the mid 70s as the reality of the RAF's inability to provide meaningful air cover over the Fleet became apparent, plus the new threats posed by Soviet missiles that could be targeted by 'Bear' shadowers). The CVS design, aimed at providing an ASW command vessel with 8 or 9 Sea Kings embarked, was hastily (and fairly late on) modified to include lifts large enough take a Harrier. The original lifts were long and narrow in size to handle a folded helicopter., From that time on, Sea Harrier ops from the ships demanded a continuous process of 'make do and mend' to make it work. The Falklands showed what could be achieved from very basic beginnings.
Which, I think, brings us to what the F-35B might or might not be able to do from smaller ships. The F-35B was specifically and deliberately designed to be able to operate, and be supported from, a USN 'Wasp' class LHD. These have a displacement of just over 40,000 tons, decks about 840 ft long, just over 100 ft wide. But no ski jump.
The B was also required to be able to launch from an 'Invincible' class deck and ski jump. Flight deck was about 600 ft long.
Izumo has a lower displacement (27,000 tons), but a comparable deck size to the LHD (814 ft long, 125 ft across). Again, no ski jump (yet). At a guess (yes, just a guess), her lower tonnage is because she doesn't have a well deck and all the amphibious assault stuff.
Dokdo is smaller still. 18,800 tons displacement, 650 ft long, 102 ft wide.
The RAN's Canberra class are in the middle of the pack - 30,000 tons, 760 ft long, 102 ft wide. They already have a ski jump
Warning - opinions here. I'd think that very useful F-35B operations could be conducted from Izumo (with a ski jump) or Canberra. Dokdo looks extremely small, but if all they want to do is 'lily pad' a few F-35Bs up threat, then a ski jump might make it happen. Tight, but possibly achievable, with a bit of determination and old fashioned ingenuity.
A bit like Sea Harrier operations from the 'through deck cruisers'.
Oh, and I think the F-4/F-35B size comparison goes like this:
F-4: Length 58 ft, span 38 ft, weight 61,800 lb
F-35B: Length 50 ft, span 35 ft, weight 60,000 lb.
I do think that the F-35B's a little smaller than an F-4, but weighs about the same. But it doesn't need cats and traps.
Hope this helps a little,
Best regards as ever to all those looking to put aircraft on ships,
Engines