I have this same problem. I fly a CAP 232 from yellow aircraft and the only solution I have come up with is that there is none. It is merely a design flaw/attribute i guess. Theres realynothing you can do about it from structural standpoint. I have split elevators with a "y" in the pushrod, pretty much exact same setup as you, and i have the same issues. I just use the plane as a speed demon and use elevator throw gently. I only havea 25-30 degrees of throw like you and mine still snaps. It rolls like a dream though!