I have just showed you a one-way ticket with a partner, but it costs as many avios as the return booking. Personally, I earn on IB but do most of my redemptions on BA (mostly US domestic s-h). I have to call to transfer the points but, thankfully, there is normally no wait on the IB+ line and this is easy. The IB+ systemis just not good for redemptions on parterns and, yes, the webpage is glitchy and often does not show all the available flights.