One thing that is not emphasized strongly enough on this topic is that it is very difficult to envision a scenario in which there would be a positive reason to increase the coin supply beyond the current plan. Adding more coins dilutes the value of existing coins, so the current community of bitcoin users will naturally oppose such a change. Miners might like the idea of earning more coins with an enlarged block reward, but the course of events with the recent UASF and resulting SW2X outcome vs. Bitmain's efforts proves that miners who oppose the market will be forced to back down. At worst miners would create a "21M+" fork, and users would support the legacy fork, forcing hashrate to shift back to the economically valued chain and defeating the attempt to change the coin supply.