There is no need to burn anything. If the only problem is that developers can access premine instead of miners, it can be just moved to timelocked addresses that anyone can spent in the future. And if such coins should be accessible only by miners, it can be easily done by Miner Activated Soft Fork. However, such things probably will not be needed, because if something is sitting on address that anyone can spent, then literally anyone can spent it, including miners. And in such cases miners always will have an incentive to reject some user transaction spending these coins and mine their own transaction sending these coins to themselves.
To sum up: if the main problem is that a few developers hold a huge amount of coins now, it can be just send to many outputs with timelocks in the future, then it will not be possible to spend all of them now. If only timing matters, it can be sent to the same addresses, then just developers will spend it later. If it should be accessible by anyone, it can be sent to address that anyone can spent. If it is difficult or impossible to create such address, all that is needed is just using normal address and revealing its private key.
Everything you've written is a theory that doesn't have any basis for when, what and how it will be done. We are talking about full trust not only of miners, but also of future users of this coin. No one will use the services of the project on dubious promises that the premine will be honestly used or shared. We are now talking about the economic and political component of the project. The premine must be burned in several stages before the coin goes to the exchange. In addition, constant donations of 5% for developers should also be stopped at a certain block, after which all rewards should remain only for miners. Only in this way will the project inspire complete trust on the part of any users, if it is truly unique. All coins that had a premine or endless donations from mining, after entering the exchange, suffered a fiasco, as well as 99% of tokens with a preliminary ico.