You seem to be abit confused with what the boosts are.
There is a Well of Goodwill Boost and a Random Boss Boost are separate boosts.
The well has 8 different types of boosts it can supply [minigames, experience, godwars ect], while the boss boosts have every boss in the game [a single boss].
The well is just a random global boost, to allow players to participate in Boosted activities randomly throughout the day. If you want a static boost for the boss you want to kill purchase a 1.25x boost scroll from the Bond store, this way no matter what you can gain a drop boost on the npc you and your friends are doing, rather than relying on only doing it when the Well is on.
Each boost is equally weighted and complete random to be selected at the end of each hour. There is no set time for each different boost nor would there ever be, nor would be add it in a static rotation.
A [next boost] option isn't viable too as the boost as mentioned above is just random upon the change, not to mention these can be affected by other means from higher staff.
