Hi, Mary,
I think you could, perhaps with a bit of engineering, change the canopy for a different one (probably for the Bugaboo Donkey one, but you would need to buy the extra canopy wires and canopy clasps, which will cost quite a bit), but I must say you will not solve the problem you have, as the hood HAS to be over the seat's end, or it will just stick out and move around with a huge gap in the back.
It is a thing with reversible seat units (more about those here), they are smaller, it has nothing with the weight limit which is almost always a bit overstated. My recommendation would be not to invest too much into your stroller, rather to use it as long as you can, and then get a non-reversible mid-size pushchair in the style of the Oyster Zero which suits a larger toddler better.