Have similar ideas, using 3/8" rnd, welded struts or a cobbled up, bolt-on version to see if there's any real gain.
30 to mid-40mph speeds just need a bit more rigidity, not necessarily a full fork replacement on low budget builds. One area where Hobbits suck, even if the wheels are true. Helps to know someone else was thinking down the same lines. ..Thx!