Hi erpbridge,
Regarding this topic, please note that we do not manually process large bets, all bets are confirmed automatically by our system regardless of the height of the stake.
In case of a Livebet it can take a couple seconds more as the odds are changing in real-time and in some cases the bet can be rejected as a result of that.
To have the highest chance to have your Livebets accepted you can put a checkmark in the 'Accept all odds changes' box, this does mean you accept any odds change.

Cheers,
sportsbet.io
Thanks for the reply. I don't anyways make really large bets for now, but in the future will keep that in mind. I am also glad to see the awesomely fast new UI guys have started implementing now. Definitely has made a difference in betting.