Not sure what you mean by "fix ACT", I mean for fixing something there must be a bug. ACT has several, but for many of them there are reasonable workarounds.
Cakewalk has "Control Surface Interfaces". In is in C++. Some have it in JavaScript, some in Python. It is hard to guess what exactly you want with "add".
Controlling several synth parameters is sometimes implemented inside Synth in questions. If parameters are automatable, it is possible to group control them in Sonar. If parameters are (can be) steered by MIDI, MFX can do the trick.
So it looks like you request implement better (simpler to setup and/or more sophisticated) parameters grouping. With that I agree, that part can be improved. But the title is somehow unrelated...
Note that in this forum it was mentioned several times that different products are better for different purpose. "Universal" music program, which is the best for any music tasks is not yet written. Also as soon as you implement more features, the program is unavoidably become more complex and harder to learn. The effect you have just hit yourself, comparing "ACT MIDI plug-in" with AZ Controller
Last note: grouping in Sonar work fine with ACT as well as with "Remote control", the later is may be simpler to start with (but select unused CC for the control, Sonar does not not block assigned remote control MIDI messages and that can clash with direct reaction on that messages).