First, Mopars are not "notorius" (sp) for bump steer. Compared to many other muscle cars they have
less bump steer. For example, bump steer kits are everywhere for 60's and 70's Mustangs. You don't really see them for Mopars, Hotchkis is the only one that makes something that could be used that way and even they don't advertise it as a "bump steer kit". If it were a big problem you'd better believe someone would be selling a product for it and making a ton of money, because they're a pretty simple thing to make.
Toe change is just a fact of suspension geometry. It's always there. Better suspension designs have less and there is what's considered an acceptable amount (which most Mopars are usually close to or under), but toe change is never zero and making the tie rods perfectly equal doesn't change that. Toe change is generally considered to be acceptable if it’s less than 1/16” per inch of travel. So for the whole range of travel on these cars you’d be looking for less than ~.34” of toe change.
When Bill Reilly did the toe change measurements on an A body for the FMJ spindle swap he was getting less than .1” of toe change for the whole 5.5” range of travel he measured with A-body spindles and less than .2” of toe change with the FMJ spindles. You can see the results he plotted in this article. Either way, it shows A-bodies have pretty decent bump steer with what would be considered fairly normal suspension settings.
https://www.motortrend.com/articles/mopp-0503-swapping-a-and-b-disc-brake-spindles/
As for the uneven tie rods, yes, the length of the tie rod does have an effect on the bump steer, but you have to keep in mind that straight from the factory there is a significant amount of tolerance on the suspension mounts themselves, so depending on the car it may not be possible to have the tie rods equal lengths because the suspension mounts themselves may not be symmetrical.