To make sample polyphony possible without squeezing additional voices out of the hardware, channel/alternate could be set to a MASTER or OMNI mode, where the sound would be given Master Priority over all output choke groups.
A track with Master priority would always be at the front of the line for polyphony allocation. This would allow a single sound to be played with up to 8-note simultaneous polyphony by allocating the newest note to the next unused output. Once all 8 outputs are in use, Master Priority choke would kick in & override existing sounds, going from oldest → newest.
This mode could temporarily override filter settings for each output and allow all output filters to be controlled via a single knob. Or even better, this mode could grant a sound access to all 8 filters so that you could fine tune the filter of each note in a chord, or each hit of a drum break.