No such thing as the most paper champ, lol. And it's irrelevant if didn't win the belt from the prior champ. He fought for the HW title and beat Gane who is among the top 3 HWs of this decade in 2 mins. Now he's HW champ. It's as relevant as it gets.
There's as much a thing as 'paper champ' as there is 'champ'. It's all made up. Every promotion has its own 'world champion'.
What matters is how much credibility we inter-subjectively give these titles. Boxing alphabets mean something or they mean nothing.
The MMA HW lineal championship means a lot because it is unbroken. Jones is not the lineal champ. He is just a 1-0 HW that beat Ciryl Gane - a non-champion.
The only credibility he has as a HW champ is manufactured by the UFC's marketing team.