I think what would finalise this synth for the modern domain , is to revamp the envelop 3&4 section so you can draw out any curve and where ever you wish to , abit like what Serum/Massive has - although envelopes 3&4 could be used in a similar way
Or can this be done with the Arp to matrix but add the ability to shape any curve within the arp section , or as I say , revamp the envelopes 3&4 , and add some curve style presets adjacent to the section and in conjunction with the LFOs as to produce drawn curves for those also , I could also imagine that looking sweet in the arp section
Cheers
I