For 1x1 it is quite simple to me. Establish you'd like something once a week and want communication if it will take longer. You now have an 'official' premise before anything begins to poke them after a week. I go further and universally hold that after a few weeks and a couple prods, I shelf the roleplay temporarily and wait the rest of the month. If a full month passes without communication about leaving, I drop them with no regrets whatsoever. If they were just legitimately offline, I might pick it back up if they show up again. If they were frequently online and obviously ignoring me, bonus points for not saying boo while posting elsewhere or straight up looking for another partner, they can fuck off for the rest of their tenure on the site. Had plenty of each occur.

There's a few more conditions, but that's the gist, and in the event it's an announced absence, I'm much more generous with my time table and am completely generous if the given partner just doesn't feel it and tells me so. Key, though, is poking a few times first.

Still expect frequent failure with any higher amount of partners and adjust your expectations to expect very little. Disappointment will not come often for that.

As for group roleplays.

[quote]"They'll post when they can" was my thought[/quote] oh, ye sweet summer child

Public roleplays have all sorts of factors for failure. One that applies here is a lack of investment and/or obligation, paired with attitudes like "Just another roleplay, fuck it", "dammit I forgot about it", "I don't feel it anymore but I don't wanna say anything". Quite to the contrary of your new approach, double the fuck down. Again establish this in the OOC beforehand. Set reasonable waiting frames and then keep your own little strike system. Keep people talking and obliged. Have an OOC dynamic so people have a reason to come around more regularly, regardless if this is by thread or discord. People who legitimately have busy lives should be pretty clear and can get a wider berth. People who dump egregious amounts of time into other interest checks while flipping yours off and not telling you they really don't care anymore should be booted and worked around.

The gist here is to encourage your active players, poke and motivate your slower players, and trim the ones who constantly fail and lead to the apathy effect resulting from no progress. You are the primary motivator. If you lie down, if the GM doesn't take initiative, failure rate is guaranteed to rise. All of the above depends on circumstance and may not save you in the end regardless, but general views on roleplay success are out of scope right now, so I'll just say taking an active role in keeping participants and partners committed is a [i]essential[/i] to going anywhere. I consider a healthy OOC sideline and good chemistry to be pretty nifty too.