We are in same spot. We have a Como 4 & 3. Seatpost concept same on both. I just put a Thudbuster ST on mine. When pulling out seatpost, carefully because you know there are wires in there, I made sure when removed there was enough slack in wires to set post on bench or something without putting a strain on wires. There are 2 wires, black and red, DC voltage stuff, polarity, one is +, other minus. There is a quick connector, little torpedo things, that you need to disconnect. Do not pull on wires, hold the connectors. I used a quality black tape to cover ends from control (about an inch, folded over connector) and stuffed back down tube. Before I did I created a small loop in that pair of wires not knowing how far it would end up down the tube. I can now easily use a small hook to pull back up if/when necessary. I coiled the remainder, attached to seat light, under the seat and secured with a ty-rap. Understand how the underside of the saddle moves and don't let wires get damaged. Always think new bike, warranty, etc. I installed the new ST post and "the cup" saddle to new seatpost and rode away into the sunset.
I am not a fan of "the cup" saddle.
The wires look to be 20-22 guage, certainly stranded not solid for flexibility. My intentions are first to put a meter on them, turn on bike, measure voltage. That way I'll know if I decide to put a different light on existing wire. I'd also like to know the ohms (resistance) value of the existing light mounted to seat. If the wires are not long enough, a quality, flexible, same guage wire could easily be soldered onto existing for length to wherever you wanna take it. Routed accordingly of course. I'm not seeing any natural way out of the ST tube so I will drill a hole in seatpost at rear, probably 1/8" to 5/32". Just enough to carry the 2 wires and an appropriate grommet, shrink tube, or otherwise to protect wires. I would make sure to have the hole end up clean with no burrs. I doubt it will have an effect on the integrity of the seatpost. Then route to new location.