These SDRs have time limits because only a limited number of people (depending on the configuration 4 or 8 total connections, mine is configured for 4 total connections, and one of those is reserved for me, leaving only 3 for other users) can be connected to them at one time and because some people squat on the receiver for extended periods, sometimes obviously not listening to anything at all.
When I first put my Kiwi online I did not have a time limit on it or a reserved slot for me. I often could not connect to my own receiver. I had people set on the receiver listening to AM stations and baseball games for hours that they could have streamed online just as easily. I had listeners set for hours on HF-GCS frequencies, sometimes the same listener on multiple different HF-GCS freqs at one time, one listener used to regularly tie up all the slots in the receiver with HF-GCS frequencies so no one else could use it, and stay connected 12 or more hours per day. I had people, sometimes obviously the jammers themselves, set and listen to themselves on various ham bands, one person would tune to 3840 kHz and retransmit his audio for half an hour at a time. In the middle of the night I would find people that had been connected for hours on a frequency the propagation had dropped out around sundown. I connected one time and found the same person had three seasons going on my Kiwi, all on the same frequency and the same mode, and they had been connected for 6 hours.
So I put a time limit on my Kiwi. I did not put a 24 hour limit on it, just a reconnect requirement. This reduced the kinds of things I mention above to near zero. This allowed more people to connect to my receiver in a given day. And yeah, it is annoying at times to have to reconnect, but if some people were not inconsiderate that would not be a problem. If one person ties the receiver up all day no one else can use it, and that is not fair to other people. And I give the timer override password to people who I know are long term listeners or who ask for it.
Mine is in much better shape today, not only do the time limits keep people form camping on it but relatively few people can see my Kiwi as it is not listed on several public Kiwi lists. That was not my doing, it was just a fact after it was put behind a proxie.
WebSDRs like Twente can get away with no time limits because some of them (not all) can have hundreds of people connected at one time. Twente itself can support over 700 connections at one time, the highest number I have seen is ~730'ish.
T!