[DoofusOfDeath]

How about this? Say you're more than happy to consider signing it, but the company will need to reimburse you for reasonable lawyer fees so you can hire a lawyer to review the proposed assignment.

IANAL, but I suspect a key detail here is that you are hiring the lawyer, no your former employer, because that's crucial to having the attorney bound to represent your interests.

But again, IANAL, so I could be totally wrong.