What are the consequences of a low Acct-Interim-Interval?

[Houman]

>
>   And a 10s timeout might work, but it's generally low.  If you set it to
> ~300, then the authentication might restart.
>

But if I set Session-Timeout to 300 then I haven't gained anything,
because Acct-Interim-Interval is already set to 300.

My hope was to run the conditionals in preacct sooner than 300s intervals
without increasing the traffic.