(I appreciate "devote the space", but Maths should absolutely not be thought of as two Functions; it's much more for less space than two Functions).
What are you mainly using a Function for: envelopes? Looping envelopes (LFOs)? Slew? Filtering? The EOC/EOR outputs? How important is CV control?
Depending on the priority of functionality might offer different results. (For instance, Peaks is great if you like LFOs and or Envelopes, but no good for CV control, slew or EOC/EOR.)