These are the current limits enforced by Senden. They apply to everyone on the free tier, and are subject to change as the platform grows. A future low cost paid plan will offer higher limits on several of these.
Senden is considering a paid plan at around 4 euro per month that would offer higher limits and extra features. This is not confirmed. Final pricing, features, and availability may change before launch. The current thinking is:
On top of the base plan, you can donate more than 4 euro in $2 steps. Every extra 2 euro gives you 2 points. Points can be invested into a server, which will add some additional perks