It depends how you look at it.
If you want gold in mass or as historical artifacts.
Since you talked about tonnes earlier + the expectation of bars it would be better if the shipwreck dates after 1565.
From what I gathered so far from info on the net, and also derived from SFRX + archeologist analysis Juno is appraised at around 1550's.
If you're betting to find tonnes of gold you better have some big solid objects, as ingots, these ramp up in weight quickly. Whereas if you 'only'
find rings, bracelets, amulets, coins or whatever then you need to find them in huge quantities to match with the expectation of finding tonnes.
Since Juno is taxed around 1550 they can't find massive bars, hence it will be really difficult to find a ton, not even mentioning the plural as you
need a lot coins & rings etc to match a ton. Nonetheless the outcome, even a ton x todays gold value = $47 mil! Not bad for a day' work...
Its nice to dream of tonnes, but I like to keep it real, thats not always appreciated by the pumped up energizer bunnies & chimera chasers, but
at least I'm not setting myself up for disappointment, it is what is. And so far Juno, after two years, has fallen short of expectations, again, it is what it is...

SFRX should solely focus on Lantana, first of all its much more compact, not so deep and the wreck dates post 1550's, so bigger quantities can be there IMO.