I don't like most approaches that are based directly on ratios (even though I've suggested them myself before), because those ratios are sometimes way off (for an example of this, consider Symmetrick, who now has a jaw-slackening merit-to-post ratio of ~23:1 over 516 posts, but, before much of their stuff was self-deleted, their ratio was closer to ~0.77:1; still good, but, ~30 times less so). Also, if you read the rest of this post, I think you'll see that I'm advocating for something that wouldn't continually force any particular "time frame" on anyone (neither in terms of real time, nor in terms of "time" that only advances by one unit when you make a post).
But without a time-frame, I don't understand by your post how it will work. I will read the follow-up explanation you posted and if it's unclear I will ask again.
Now from the perspective of a merit source things change based on how you receive merit after you become a source (especially if you are not in a gang circling merit).
Pun intended?
I agree with Mia though, even though I am not a merit source. I suggest we leave it as is because the "carry" is good in theory and philosophy, but I am worried about the changes and the algorithm which decides the "rank / de-rank".