How can one add 'rings' to Page() command

I have some Ascom WiFi phones that I would like to use as walkie-talkies.
I have made a page group of 4970 but these phones need 5 seconds before their auto-pickup feature kicks in.
The page command only rings once (about 3 seconds) before considering everyone joined.
One can manually pickup the line within the 3 seconds and become joined - so I assume if I give it more time the phones can pickup themselves without needed to manually answer the call.
Can anyone lend a hand on forcing Page() to ring longer?

Here is the default code:

[ext-paging]
include => ext-paging-custom
exten => _PAGE.,1,GotoIf($[ ${AMPUSER} = ${EXTEN:4} ]?skipself)
exten => _PAGE.,n,GotoIf($[ ${FORCE_PAGE} != 1 ]?AVAIL)
exten => _PAGE.,n,Set(AVAILSTATUS=not checked)
exten => _PAGE.,n,Goto(SKIPCHECK)
exten => _PAGE.,n(AVAIL),ChanIsAvail(${DB(DEVICE/${EXTEN:4}/dial)},js)
exten => _PAGE.,n(SKIPCHECK),Noop(Seems to be available (state = ${AVAILSTATUS})
exten => _PAGE.,n,GotoIf($["${DB(DND/${DB(DEVICE/${EXTEN:4}/user)})}" = "YES"]?skipself)
exten => _PAGE.,n,Macro(autoanswer,${EXTEN:4})
exten => _PAGE.,n,Dial(${DIAL},${DTIME},${DOPTIONS})
exten => _PAGE.,n(skipself),Noop(Not paging originator)
exten => _PAGE.,n,Hangup
exten => _PAGE.,AVAIL+101,Noop(Channel ${AVAILCHAN} is not available (state = ${AVAILSTATUS}))
exten => Debug,1,Noop(dialstr is LOCAL/PAGE4899@ext-paging&LOCAL/PAGE4901@ext-paging&LOCAL/PAGE4902@ext-paging&LOCAL/PAGE4903@ext-paging,d)
exten => Debug,n,Noop(dialstr is LOCAL/PAGE4895@ext-paging&LOCAL/PAGE4899@ext-paging&LOCAL/PAGE4901@ext-paging&LOCAL/PAGE4902@ext-paging&LOCAL/PAGE4903@ext-paging&LOCAL/PAGE4908@ext-paging&LOCAL/PAGE5001@ext-paging&LOCAL/PAGE5051@ext-paging,d)
exten => 4970,1,Answer
exten => 4970,n,Set(_FORCE_PAGE=1)
exten => 4970,n,Macro(user-callerid,)
exten => 4970,n,Set(_AMPUSER=${AMPUSER})
exten => 4970,n,Page(LOCAL/PAGE4899@ext-paging&LOCAL/PAGE4901@ext-paging&LOCAL/PAGE4902@ext-paging&LOCAL/PAGE4903@ext-paging,d)

(New install of Trixbox v2.6.2.3)