Thanks, but sorry , surely neither of the full bridge simulations is ("genuinely") on the border of discontinuous operation (but please see below), if you look in the L3 current, it is continuous in both cases....*however*, your point is extremely valid, because even though the output inductor is well inside continuous operation, in the primary, it does indeed appear to be bordering on the discontinuous......As you know, this is due to the magnetising current in the primary being negative for a little bit of each switching cycle, which brings down the primary current and makes it look discontinuous.