It sounds like you're stacking a pile of these to add your third dimension.
Make a sandwich of straight strips.
You can accomplish by breaking your shape up into two versions made of straight, ¾" strips. Take the following simple example. By stacking Alpha-Beta-Alpha-… the corner is well-reinforced. Perhaps not as strong, but strong enough. Quantity is key and you have that by the bucket.
I've no idea what this technique is called. Answers on a postcard.

Build yourself a cut list for both versions, turn a load of sheets into ¾" stock and take it to the mitre saw. You're going to save yourself a ton of OSB this way but more than anything you're going to save time. You're going to be able to set a stop block and cut up to copies one after another.
You're going to save so much wood, you might be able to upgrade to a nice ply.
Glue up becomes interesting. Build yourself a template, or a negative and that can help you align things. Don't be afraid to do this in multiple steps. Normally I would say you could assemble each stacked part first and then assemble the shape but the quantity and the material would make this too tedious to try and bring together.