I think the big problem when trying to make the competition faster is not the amount of cards to make each phase but rather the fact that making a whole consistant set to restricts design opportunities which leads to "pack filler" design and creative burnout. Any contestant can probably make 7 or 8 interesting cards based on one concept, be it a class identity or a set mechanic, but then the last few cards are gonna be rushed, less interesting or out of place. I see two ways around this but there probably are other solutions.
My first idea is to ask for cards from different sets during each phase. I elaborated on this earlier but basically make 2 or 3 cards from 4 or 5 sets each phase if it's a class competition and for an expension make 10 to 15 cards around a mecanic each phase. Phases should be 7 to 10 days long.
If you want to go beyond a 15 cards/10 days, my solution would be to give the opportunity (if not the obligation) to compete as a group. I would do this with a twist tho : Phase 1 would be a "form a group" phase to let contenders pitch their ideas and find partners. If it's a class comp, everyone gets to post up to 3 hero powers, up to 3 keywords, up to 3 unique mecanics and up to 15 exemple cards. Flavor would be loose this round but it could be reworked latter. Then, people can contact each other to form a team of 2 or 3 for the rest of the competition. Teams can include people who posted or newcomers who liked the poster's concepts. On phase 2, teams would have to settle on a hero power and a keyword from one of the posts among the team (minor tweaks might be allowed), decide on a clear class identity and make to whole basic set. You could even go as far as including the classic set to but that might overwhelm those who didn't team up. After that, you can either do one, two or even three sets each phase. With this model, you can get the whole of standard done in 4 phases. If it's an expansion comp, you do pretty much the same except the first post will feature up to 3 keywords, up to 3 "one per class" cycles (i.e. spellstones, forbidden spells etc...), up to 3 unique legendary patern (i.e. legendary spells, legendary weapons, quests etc...) with up to 15 exemple cards. After the team-ups you can make 3 or 4 phases that will showcase one third/one fourth of the expension, maybe do a phase about single player content or maybe do a separate competition for that.
I know teaming up can seem like it will give certain contenders an unfair advantage but bringing several perpectives together is in my oppinion the only way to archieve a card/phase ratio that allows for a short yet complete competition.
The big thing we come up against time wise is the community backlash; People used to regularly badmouth us for having the contest run long, and usually it wasn't people competing. As such, we're trying to look at both ends of the scale (I've stayed up really late getting cards done before and McF's Sea Witch concept was literally made in the five hours before the first wave ended) but we have to be aware that there are some... vocal opponents, whether or not we fully understand why they feel the way they do.
I get that but then how which time frame would you mods be confortable with ? I don't think you can get below one month without putting enourmous pressure on contestants. Being rushed to produce full sets in a few days by myself just to please some vocal audience members who aren't affected by the time pressure would make me quit the competition because I know there are gonna be some week or day on which I can't get anything done and that is going to crush my chances in the competition overall.
I prefer expansions over class creation, but I do enjoy large contests. The reasoning is I feel there's a lot more room open for exploration of unique themes and concepts, or lesser used ones with that than any class. It's what kept me tethered here even I didn't always compete or make as many comments as I could, I did try to vote in every round. Weekly competitions are fine, but they don't get me going every week or inspire me to participate.
Also, unrelated. Is Hearthpwn Still shutting down? I sort of moved away from here because I thought it was dying. It turns out this is not the case?