There is no saving on commission with IB when you trade a "combo" instrument.
So, unless your strategy really, really requires perfect synchronisation of legs, you gain no benefit trading e.g.a straddle in one go, except for some simpler position handling.
However, with options it is better to execute "bargaining" within the spread (with limit orders) - so pricing/executing the whole combo at once can be faster/better synced than working 2-3 separate leg orders.
Supporting combo orders in a plug-in should not be difficult.
Lets organize a small riot to kindly ask for improvements to the current IB plug-in (both speed and features).