How about just setting hptimeout in a udc or something?

:help hptimeout
HPTIMEOUT   A variable used by the CI that lets a user set timed CI
            reads on $STDIN. A positive value indicates the number
            of minutes the CI waits for input.  If a timed CI read
            expires, the session is logged off.  The initial value
            is zero, which means no timed reads.  Type= W I PL

  -Chris (remove nospam) Bartram