I think the cap can go up to 4K every day if you are very active. It decreases every week if you reach that cap. How much? Not really sure.
Full info from ICE here.

At least moon scroll limit goes up. Sun scrolls stay the same. I have a habit of maxing sun scolls limit somewhere in middle of the week.

Add the fact, that Strange stones we get from either have a terrible rate (350 sun=14 stones for example) and we have a feeling active players get far less than we worked for...

The weekly moon scrolls limit gets lower week by week for me as well..from 80-85k went down to 44k now, i already hit the limit. I thought it was supposed to be the more active you are the higher the limit. Does it really decrease if we reach the limit every week?

I think it's something like this

Limit goes up by 4k a day, reset on monday to 40k

Half of the limit you haven't used by that time gets transferred to the next week. So if you were at say 40k/80k, you would start monday at 60k

The more active you are the lower the limit, not the other way around.

I think the system is kinda weird, but maybe its just me..

Anyhow, even if you don't reach limit its not only the upper limit get transferred over the next week.

The starting amount also get transferred. On the other hand if you reach limit the starting amount is reset 0.

So the totally collectible amount per week is not to say lesser if you reach limits IMO.

Going by this system, I figured out it's still about the same so might as well just max it anyways.

Am not sure what tencent is thinking when they decided on it.

But if we really investigate maybe the amount you can collect if you don't reach limit is even lesser.

So that for some who find it hard will eventually still reach limit and collect some strange stones.

Edit: If my observations is wrong, just ignore this post, i didn't really bother much to study the difference btw reaching limit or not.