I would really like there to be a grace period for the time it takes before the "Edited on" message appears on a post a regular member has edited. I do not want to allow any member to edit their post without it saying so because then people can easily edit their old posts without us noticing. However, it's really annoying for users who make a small typo or want to re-word something a few seconds after posting. This is default and expected behaviour in competing products. I'd really like Invision to make this the default behaviour in 3.4 or at least give us that option out of the box.

Is that what you're looking for?

If so that's under the "Edit User Group" and then "Forum"

There's a paid hook "(Wolf) Enhanced Edit Permissions" which will do exactly what you want (and more if you need the extras):

That does sound like what I was asking for although I wish it was standard rather than us having to pay $10 for...

Is that what you're looking for?

If so that's under the "Edit User Group" and then "Forum"

Sorry, I mean before the message appears. With this method, they can't edit at all after a few minutes.

I know what you mean :) , you want something whereby the poster probably cannot remove the 'edited by' line at all but if they edit their post within say a few minutes of its first initial submission the edited by line will not show.

you want something whereby the poster probably cannot remove the 'edited by' line at all but if they edit their post within say a few minutes of its first initial submission the edited by line will not show.

I use "Post History" http://community.invisionpower.com/files/file/4876-pav32-post-history/ together with "Enhanced Edit Permissions" (where I only really use the time grace period part of it), which means the poster doesn't see the "edited by" line when edited within the first X minutes, but only admins can see what the edit was (which is how I set it), in case the edit wasn't something simple like a spelling edit. But... it's true, both being paid hooks does make it rather expensive.