I want to record in Mid-Side mode. I would do this by recording a stereo audio channel. The left channel carries the MID signal, the right channel the side signal. In the first plugin slot I like to have a MS deoder plugin, that converts the two signals into the final stereo signal, so that I can hear what the final sound will be.
At the moment, PT 12.4 does not include ANY (!) MS decoding plugin. My wish is to have a simple plugin in DSP (to use it already during recording) and Native versions for that purpose. It could also be an enhancement of the "trim" plugin, that could by the way be enhanced to work on stereo and up to 7.1 channels (at the moment only for mono channles available). Another option would be to add the MS decoding feature to the "channel strip" plugin, which would be my favourite method.