I suspect the welded crankcases you mention have similar structural importance as a welded Hemi block does relatively in a TF car? You can do it, but nobody likes it?

I also suspect we are now no longer talking airliners?

I still doubt XV has 12 pages of detailed requirements for welding, which I listed, and those often require an in depth engineering sign offs to permit a welding repair of an alum crankcase.

I don't see how gluing anything here relates to the original topic of downsides of welding primary structural alum on an airliner as an intended design solution. You seem to be completely overlooking the long commonly understood downsides to welding alum in this specified application.

We are now going in circles.

Others have, I believe, an informed multi sided discussion here to decide for themselves, what they are comfortable with that is welded, alum, and is structurally loaded, in their cars.

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.