I have consistently exceeded the prop size recommended for the brushless motors I use preferring to reduce the battery stack a cell or two to keep the current draw in check.
The benefits of doing this are that a larger prop running slower is more efficient than a smaller one running faster and there is less weight in the (cheaper) motors.
Anyway weight saving is obviously not a help if you can't take a lot of structure out from the tail end.
If you're having trouble sourcing larger three-bladed props, have you considered the DIY route?
2-blade props are far cheaper and more readily available. Make up your own 3-bladers and you can save 3/4 of the cost.