How to switch the sound of one layer while the other layer continues playing

Dear fellow musicians,
I have set my controller in split mode and have set the different layers in Iridium on midi channel 2 and 3. Playing works fine, but when I change the patch for one of the layers, the other layer also stops sounding. How can I set the Iridium up, that the not changed layer continues sounding, so I can smoothly transit from one patch to the other?
BR Ruud

I would be very pleased with such feature, but I fear it's just a dream.
In case not, please post here.

I have a similar issue, need to be able to use MIDI Program Change to switch the patch on individual layers. It's a bit weird that this is not possible, I'd say...