MikroTik HotSpot | session expire timer/MAC-Cookie - after reboot

Hi folks!
I’ve already been a bit concerned with the HotSpot-Feature of MT.
Now, I’ve a RB1200 in operation with different user profiles (time limits and qos) for wireless internet user.
I’am excited what is possible with MikroTik - logging, debugging, great and detailed view of authorized users…awesome!

But now one question - for example, I’ve a user with a “one-week” account.
Three days after his registration (also 4 days left) - the MT needs a reboot (of another reason).
The MT comes up and the “session time left” counter under the “Hotspot Active” point is empty, the MAC-cookie are there,
but the “expires in timer” has reset and it shows the initial value of seven days.

Is there any possibilty, that save the timestamps of the login, so that does not change after a restart for the user?
Another question, how much user can be managed by the MT-Hotspot, there a any limitations/recommendations?

Thanks in advance for the help!

Greetz, maddixx