I think the problem here is simply if you read analogue/digital hybrid and think this automatically just means DCOs a là some DSI synths then you will believe that the description in SoS is incorrect.
Forgive me in advance if I am telling you what you already know. As with all forums you don't always know a lot about the background of other posters… unless they are Amos or DemonDan that is
My reading, and here I declare here a background of being both an Electronics Engineer and old enough to have built my own synth back in the 1970s, is that the 'Signal Path' of the Sub37 from Oscillator through VCF and VCA is entirely analogue in true Moog tradition BUT there is a lot going on digitally to support this.
Some of what follows might be guess work but….
Unless I am wrong the keyboard will be scanned digitally otherwise you could not derive paraphonic or polyphonic key presses from tapping off from a simple resistor divider tree like in the good old days
. The keyboard position of the note or notes pressed are read by the processor which then outputs to note value, via a DAC, as an analogue CV to the VCO(s). This allows the processor to digitally add or subtract both an octave shift plus, if required, a small 'fine-tune' to keep the keyboard on track. Meantime the MIDI value(s) are also derived and output
The three curve glide options and legato/mono mode are likely to be digitally determined from one note to the next and output as a sliding CV to the VCO(s). You only used to get the exponential glide curve in t'old days due to the charge curve of the glide capacitor (I guess that is why that curve is still simulated).
As I read the SoS article and, I think Amos on Youtube, the Envelope/Contour Generators are also digitally derived before being converted to analogue CV for the VCAs.
The front panel is read digitally before conversion, where required, to analogue CV.
My reading of 'hybrid', for the Sub37 is … analogue where it matters supported by digital where it is needed