Exactly the same sort of idea. I find the P90 method of mounting to be a bit wobbly, but that's the nature of the beast unless you choose to 'engineer' something of your own to replace what is IMO a slightly flawed method of attachment.
"Flaw" or no flaw, though, I love the sound of my LG, which has SD P90s in it. Once I got accustomed to the slightly 'wobbly' feel of adjustment, I forgot all about it. I anticipate that when you mount them, your first reaction might be the same. "What's this then? <wobble, wobble> Doesn't seem sturdy!" Don't worry, though, it'll be fine. Is this for a scratch-built guitar?
Greg