This forum always has threads from spammers taking up much of the first page of each sub-forum. And those threads remain there for a long period of time, probably the reason why they keep coming. I have never seen anything like it.
I believe all the moderators are Roku employees, so it's understandable that they may not be here outside of work hours.
I would suggest that you put a few of the long time forum members on the moderating team, people who are here at all random hours. This way they can delete the threads quicker and make a better forum. There are many members here with a long history that you know you can trust.