I am one of the ones that has been posting often, which I see in other discussions as perhaps discouraging postings by others, especially not as frequent users.
Depending on the time of week, a posting on the front page stays up a day to two, so it is not as if there is a line waiting to get in. Although I won't be keeping up the pace of these past few weeks, I do intend to post what I got.
Perhaps an option could be put in to publish a (public) story just to groups (not just private), and not the front page.
Another thought would be, now that you ask, a split front page - prime left side as is, right side (1/2 or 1/3 screen?) last two weeks, oldest at top, without the excerpt to save space. At the bottom of each side a (more . .) link for what doesn't fit.
This would give longer exposure for the infrequent poster's work, as the front page seems to be where a large portion of the community starts their journey through f'naut, while still giving prime to the current front page as is.
My guess is it might mean shutting down the site for a few hours, but that could always be done at the expense of those Aussie's and N.Z.ers down under. (Had to do that, ouch, my serious side hurts, hasn't been used for this long in decades).
Or, rather, the right side of the front page, the favorites be replaced with the last 2 weeks, and put into a boxscore type thing with the top two and a link to the expanded list.
I don't know if any of these are needed or desirable, just supposin'