Every time I want to do a certain boss without an instance, someone is 95% of the time there. Usually after their slayer task is complete, since I am not that type of person who just steals a kill from a boss. If it is finally my turn to kill the specific boss, a random person comes out of nowhere and steals all kills (after I make around 2 to 5 kills). This can frustrate if you do your slayer task or hunt for the specific pet.
My suggestion is that there can be a possible instance for these bosses. I am talking about these two bosses:
1: Thermonuclear Smoke Devil
2: Giant Mole
The costs of these instance could be as high as KQ (around 3 million coins), since these bosses don't drop very expensive items (unless you count the occult necklace and the smoke battlestaff ofcourse). The price of the instance can be changed of course, I only leave a suggestion and it is for the staff to decide if this is a good idea :) .
Let me know what you think !