While not an exact answer to your question (because I honestly don't know), I would like to offer a couple of things for your consideration.
Most people prefer fewer antennas, so consequently most radios are made to cater to them. That means those of us who want separate antennas are the ones stuck buying a duplexer instead of them. Duplexers are cheap because so many people use them specifically for this purpose. Consequently, I would very definitely choose my transceiver based upon more important criteria (like functions, features, frequency range, power, size, etc...) than how many SO-239s it has on the back. I think you'll be happier with your choice that way.
Just for giggles!
Icom, way back in the day (90s) made a portable radio that had 2 different antennas on it. The Icom IC-2/4SRA. However, both antennas were not for transmitting. The radio was either a 2meter or 440 single band radio with wideband receive, 25-950 MHZ I think! On the left side was your traditional bnc jack. On the right side, there was a hole that you plugged the receiving antenna into. Icom made a poor attempt to make a wideband antenna by puting a rubber duck slim antennas about 5-6 inches long with a 1/8 headphone jack style plug on the end. I hated this thing with a passion. I cant tell you how many times I would drop this antenna because it would jiggle itself out from the jack. Anyway, that is the only portable radio I have ever seen with 2 antennas.