All Web Access connections are currently treated as part of the tlwebaccess service by systemd. This is mostly fine, but has some possible downsides as it means systemd doesn't associate the process with a user.
One obvious such downside is that the resource usage of the connection isn't counted towards the user. So any limits or balancing set up will not be enforced for this process.
For comparison sshd puts the processes in a new user session under the user slice. OTOH it does a full login, so it might not be a fair comparison.
Another consequence is that these connections are killed when the service is stopped or restarted (bug 7578).
We fixed bug 7578 by utilizing 'KillMode=process' in the unit files. We might be able to remove this fix after we solve this issue with slices.