Suggestion for how to put time constraint into PBP

OK I just picked up Dusk City Outlaws. I am considering trying it out here. The problem though is that it requires three types of acts, Planning, legwork and the heist.

Planning phases are the times that the players discuss how they are planning the heist and what legwork they need to do to get the information needed to pull off the heist. The issue is that planning phases are limited to 15 minutes of time to discuss their plans. How to translate a limited time for planning in a PBP setting maybe a challenge. So any thoughts on the matter may help me come up with something such as limiting # of post for a planning session and so forth.

One post can contain much more information than a time-restricted suggestion, though. If players like planning, you might end up with walls of text to utilize the limited number of posts to its max. I know I certainly would try to do something like this if I were a player. XD

So maybe you should also add a rule of limited propositions per post? Like in one single post a player can offer three suggestions (for example, "let's gather information about X", "prepare item Y" and "explore area Z") and other players can react to them in their next post in format Y/N, while also offering their own three suggestions as well. And then limit the number of post per player?

I think just limiting total number of posts for all the players combined might be unfair to players who don't visit the site as often, since if others use all the posts quickly, others might lose a chance to participate.

Would it be more fun or annoying to have a word limit? You can think as long as you want, but if you can't describe it within 30 words, you're out of luck. Another option could be agreeing to meet at a specified time in a Discord chat and continue with a slightly longer time limit. I know chatting live isn't really a common thing here, but maybe the players could find 15 minutes at a similar time of day?

Another possibility could be to keep the time limit, but adapt it to pbp pace. Saying "You have up to X date to discuss this" could probably work...

I think a word limit could work. Just figure out how many words 15 minutes is, and have them discuss plans until they collectively hit that limit. An 15 minute conversation at a speaking rate of 150 wpm is 2250 words.

If you do this, it would be good to let your players get an idea of many words they're using, maybe give an example or something. Like, this very post is eighty two words, and would take about fifty six seconds to speak.

This could work, maybe make it part of "character creation/game start" discussions. "The planning thread will be posted on Monday, you will have until Wednesday to plan and then the thread will be locked."

Obviously the length of that time would be up to you/player frequency discussions.