I agree with delaying solids until at least 6 months.
It's totally possible to finished a feeding in 10 min. My son is done in 7-8 min max, and that's for both sides. As babies age, they get more and more efficient at nursing.
If you want to continue breast feeding, it's best to feed on demand, not on a schedule. I know that's contrary to BW methods, but really, it's the only way. Babies know what they need, and when you nurse when they're hungry, it helps keep your supply where it should be. When a baby goes through a growth spurt, they will tend to nurse much more frequently. This will increase your supply to meet their higher needs.
If you feed strictly on schedule, your supply will remain constant and you may end up supplementing, which will only further decrease your supply.
In my opinion, bf on schedule is the quickest way to ruin a bf relationship.