I might suggest using layers of cardboard taped together as a target. No matter what the blade shape, the chance of blade damage is eliminated. U can throw inside the house too using a cardboard target.
I used to throw old British bayonets at a palm tree. These bayonets never broke and they were cheap!
Just some ideas! good luck!
Funny, I have an old British bayonet I have been throwing for 2 decades or so, and it is still going strong! I throw against wood targets of all types too!
Man, do I wish I had bought a whole bucket of those! 12 inch carbon steel blade for $5 in perfect condition (back then). The guy had buckets full!
CS makes pretty sturdy throwers (Cold Steel). Their GI tanto (although not as heavy or long as I like for no spin) has held up to years of me throwing it hard. It has been bounced off rocks, concrete, and steel. I have one of their biggest throwers too, that has been indestructible.
I took the handle off, and used heavy tape to beef up/weight up the handle.
Custom throwers will be even nicer, but much more expensive.
The cardboard tip is a good one too. Cheap and light.
My current target is over 6 feet tall, made of 4x4's and weights at least 130lb + and is a pain to move.