I have an L-35 that came with the matching backhoe.
I use the backhoe 'arm' all the time like an animal would use its tail for counter balance. I'll swing it to the uphill side if I'm on a slope. Or, I'll extend it out horizontal to the ground for a greater counter weight to either help with traction or tipping if I have something very heavy in the bucket.
Your idea of using just the outriggers from a backhoe is an intriguing idea; however, I think you'd be missing the true counter weight and that's the arm. I've done like you've mentioned and put them out for 'stability', but it doesn't really offer any stability where you need it. If you're lifting something really heavy, the tractor is pivoting off the front axle and the stabilizer arms are going to be farthest from where you really need them.