Which isn't going to help with Bottlecaps.

From memory the relevant switches in Bottlecaps are splitthreshold and combinethreshold.
The limits of these depend on where they are set, which is slightly mad.
In the .conf or command line the max is (IIRC) 200/400 whilst via the RPC is walletbalance/500 and walletbalance/250 respectively.
So to set these to maximum you would need to type into the debug window,

splitthreshold 9999999999

and

combinethreshold 9999999999

And repeat every time you restart the wallet. Alternatively you could have a script that sends the RPC commands at start up.