I was not talking about a cardioid design. I starting commenting to your post below. There is no mention of cardioid on that. However, you are now talking only about cardioid design.Not really, we are talking about two different things there. The 2.5 way construction just modifies the frequency and power response to get a flat direct sound compared to a 2 way construction of the same baffle and drivers where it has to be done in the crossover (by reducing the output above the baffle step), while a cardiodid changes the directivity in the bass and thus is taking the baffle step frequency lower. The 2.5 way does not change the baffle step frequency as this just depends on the baffle dimensions.
I have nothing though against the physics and looks of wide baffle implementations, only that they have become very rare and unfortunately also usually expensive in the last decades, which is rather a law of market.