Hello everyone,

For the transparency of this report - I will split redstone blocks behaviours into two categories:
Active - what does it do?; Reactive - what blocks does it affect?; And also to save on word count I will use made-up names for things like:
Hopper-cart - Hopper with minecart
Container-cart - Hopper with minecart and chest with minecart
Any-cart - Any type of minecart

For example: A hoppers ability to pull items from above and push them bellow is an active property and the 2 chests from which it pulls from and then transfers to, is a reactive property.

I will now present a number of experiments and briefly state my observations.

Experiment A - done for information purpose:
The hopper-cart active component only affects hopper directly above and reactive part comes from hopper above it and bellow. Adjacent hoppers are unaffacted, works like expected.

Experiment B - good example of when action and reaction becomes important:
Hopper-cart is pushed towards honey block. three hoppers can now push items into hopper-cart but hopper-cart can only pull from hopper to the left. Meaning, moving hopper-cart shifted its reactive range but the active range remained unchainged.

Experiment C - any-cart bouncing off air:
Honestly, this one is hilarious to watch. Off-rail any-cart on top of a slime block risen by a button activated piston results in launching any-cart very high into the air and first few bounces of a slime block appear to take place about a block higher almost as if it bounced off invisible block. I can't comprehend this one but it does seem relevant enough to include.

Experiment D - any-cart phase into block as if placed on ramp down rails:
Pushing any-cart towards a brick wall stop with a rail track 1 block bellow placed perpendicularly to the one above results in any-cart phasing right into a solid block. long story short, any-carts reacts to presense of two rails.

Experiment E - ejecting any-carts
Any-cart moved towards iron bar pole results in ejecting any-cart 1 block further than actual reach of extended pistons with rails. This does not happend when the same spot is obstructed by a solid block. it is relevant to reactivity issue however, I think that this particular behaviour can be useful in redstone contraptions. Could it be intended?

Experiment F - function rails react to any-cart but any-cart won't react to rails
Ticket MCPE-33886 could be indirectly relevant to this issue, maybe?. Nevertheless, at the scenario of placing detector rail from inventory resulted in rail only being able to give redstone signal output through comparator. for the sake of precision of results, piston is used to push function rail at the place of iron bar. At this point, detector rail reacts to the presense of container-cart but when activator rails are pushed instead and then powered, they will not deactivate the hopper-cart. This indicate that any-carts are in range for rails reactivity but the rails are outside of any-carts reactivity.

In summary, based on the observation, I can consider the fallowing statements to be true:
Active behaviours of anycarts can only be trigged by the exact same rail that supports it. If minecarts are pushed any further than iron bars that are used to stop them, they fall off rail resulting in shifting to next rail accordingly.
Reactive behaviours of any-cart require itself to be at a pixel deep inside adjacent block that is also a reactive part to any active component from elsewhere.

Clearly Active elements are Data-Driven and Reactive elements are Hitbox-Driven.

These are merely the ones that I am aware of and I couldn't find any directly relevant tickets (apart from MCPE-33886) and I firmly believe some of these behaviours are a by-product of a hopper + hopper-cart serializing control which is better described in the comment section under ticket: MCPE-94293.

Honestly, I am very uncertain of the level of impact these can have on players and truth is I came accross them while studying MCPE-57637 issue. I wrote this thing down with mentality that "it is better to write it down and have it closed than not writing it all" of course until these go out of control at point of which I assume, a lot of people would make their own tickets.

Thank you very much for your time.

Attached content:
Screenshots of "Experiments"
.rar archive of MC world that I used for this