My company invariably buys last minute ow tickets for me. The policy is cheapest available and I've tried explaining that it might work out better at times to book a changeable return, at least for the times where we have a idea of where I'll be returning from.

On the plus side though, all that's usually left is T+ so that works for me.

Downside is I never need to worry about upgrade windows since I never get a ticket till the day before I fly in the first place.