I wanted to add my contribution about which tournaments would (imo) potentially do well as Zone30s, and where we need some regular freezeouts. Times are in CET (GMT+1) for clarity's sake
4-5PM
Ring being back is good. We need to have a regular decent-guarantee freezeout to kick off the day around this time
5-6PM
The 5.30PM 20€ 6max turbo could be a zone30? It's 400GTD currently and barely gets 20 runners.
There used to be a 5.30PM 10€ deepstack holdem that's now gone
it seemed to never attract more than like 60 runners for some reason. I think you could maybe put a regspeed rebuy here (since it's quite early on, a bunch of people would late reg it towards the end of late reg and it would get more runners that way). I definitely think there should be something else here than just the 5.45PM 5€ monster stack because it starts so deep and goes on forever but no one wants to actually reg it before like 7PM. Again it's really really bad to not have a normal freezeout in the 5-20€ zone during this hour. If there was a proper MTT here people would also reg zone30s and whatever on the side.
6PM-7PM
The 6pm 10€/200gtd 6max regspeed would make for a great zone30. Same for the 6.30PM 5€/100gtd semi-turbo. Both of these are completely pointless tournaments as is and can't get any worse
7PM-8PM
The 7pm 5€/500gtd regspeed fullring is nice, please don't change it or if you do, replace it with something similar and not a zone30. The 7.15PM 5€/300gtd 6m turbo would be another zone30 slot candidate, same for the 7.15PM 20€ 4max 400gtd. It's a bad time to have a 4max MTT, too much stuff going on which is why no one plays it (4max takes lots of focus).
8PM-9PM
You have a bit of a problem slot here because you are missing a proper nice full ring MTT. Just do a 10€ or 20€ xxxx€ guarantee regular speed full ring, nothing fancy needed. I like Kamikaze (the 5e 6max rebuy) but I don't think this is an optimal slot for it. The rebuy period goes on so long that it's pointless to have this MTT in this timeslot and that's why it doesn't get a lot of players. I think Kamikaze would do better 1-2 hours earlier. I do hope it won't get taken off the schedule though as I like it 100x better than zone30s.
9PM-10PM
Even a bigger problem slot here. Please get rid of the 20€ win the button (if you want to have WTB, put it earlier/later in the sched) and give us a 10-20€ freezeout. Joker was great, something like that pretty please? I know it failed to get huge numbers, and honestly I'm very puzzled why that was. Everyone I know played it and loved it and it was one of those mtts we always really looked forward to. If I would've had to choose a favorite tournament on a weekday, Joker would have been very close to the top of that list. When the WTB started everyone stopped playing it. Similarly Booster was great. We really really really need normal (may it be KO or not) stuff here, BADLY. It's epicly terrible to have zone30s here and not flagship primetime regular tournaments. This is the timeslot that needs fixing the most. Also the 9PM 5€/300gtd halfturbo 6max would be a good candidate to be changed for zone30 as it's a pointless tournament for a peak timeslot.
10PM-->
I think later into the schedule is a pretty good time to trial Zone30s again.
Basically, tl;dr version:
-You need more normal freezeout tournaments during peak hours. Your schedule is currently very weird in that regard. You have all kinds of weird stuff, and very little normal mtts
-You have too much weird filler-like the stuff, which are mainly all 6m turbos or semi-turbos with 30-40 player guarantees. Like the 9PM 5€/300gtd is just a completely absurd and pointless tournament at the peak of all peak times. If you want to put zone30s in the sched, these are the tournaments you should target to change
-Not that important compared to the other points, but I think some sort of rebuy regspeed MTT at around 6-7PM GMT+1 would do really well. Either way we are really missing a normal freezeout or rebuy or whatever (regspeed, fullring) at around 5.30PM-6.30PM. The monster stacks don't help as they only actually "start" like 1,5 hours after their start time.
All of the above is what I would honestly do as a poker site manager as well, I'm not posting from a maximizing profits point of view at all