I'm trying to find the recommended way to implement a mono patch supporting portamento on overlapping notes (where the second note is offset from the first), since that seems to be a common way to handle portamenti in several hardware MIDI synths. 
It seems that default oscillators (sine, square, saw) don't respond to MIDI CC5 (Portamento).
I'm sending two overlapping notes one after another to a monophonic oscillator, but I don't hear any note slide. Is there something I'm missing, or do factory oscillators don't respond to these CC messages? (I'm using the
midi/keyb note object as an input to the oscillator).
Should I directly add CC5 modulation to the tuning knob on the oscillator? I suppose not, because it seems more likely this is the role of the pitch bend CC, since the CC message would definitely change the tuning until the next CC5 message, it would not "tune back" to normal once my two notes are over.
I own the Getting Started with Axoloti book by Jan Vantomme, but aside from indicating the CC messages related to portamento (that's where I saw there are 3 dedicated messages to Portamento control, CC5, 65 & 84, but I'm not sure how to use them to get the effect I want, and I'm not even sure which oscillators have support for them) it doesn't describe this matter.
 I know of some other synths which have a "global" glide mode, where the synth always remembers the last note played, even after it's OFF, and when a new note arrives it slides from the old note to the new one. That's not what I'm looking for.