Flat, sloped, or stepped?

So why did Bertram use a curved/sloped sheer line on the 38's and 33's but go to stepped on larger sizes? The sheer line was flat on smaller boats 25, 26, 28, 31, 35. The 38 wide-body was an old model and maybe the slope was consistent with early sportfish boats of the time. But then Bertram went with a stepped sheer on the 46. Would be interesting to understand the design reasoning at the time.

The 38 III probably had the slope for legacy reasons, like its predecessor. But it was designed into the 33 when the 35 was flat? Maybe because the 38III and 33 came along at the same time?

I think the 42 and 58 originated on the design board as trunk-cabin motoryachts and then the hull was used to design a sportfish which would be why there is a large step and flat bow instead of curve like the 46. The 46 went the other way which is why you see the sheer line curve on the 46 MY even though the deck remains flat.