I would agree that I think he's better off going for the UCI (track bike) record, if he is comfortable in that tuck. When Boardman started training for that record he felt he would top 50km. But it's harder to sustain than one thinks, he truly was at the end of his career, and barely beat Merckx record.
When Chris set the Aero record, he was in the pinnacle of his life physically (Superman!), and put in a tremendous effort that day, afterward said he was completely exhausted at the end, and his back was killing him for the last several km. Considering all this, despite his having a treat aero tuck, I'm not 100% convinced Spartacus could top this record, which has stood for 13 years now. I think he's better off going for the UCI record.
I would also think Canc would have to prep his season late, making sure not to peak in July or even September. But race there to get the fitness. Then, in between that time, work on the track as possible. Then when the season on the road is over, shift to the track and focus for two months like a laser to peak in one specific week in probably November, and give it a shot then, with this being his main goal for the season. Not the worlds, not the Tour or Vuelta, not anything else.
I will say this, considering how dominant he was at the World's this year, just completely crushing everyone, if there is anyone in this era who could do it, it would be him.