Using a Wrench on a block to change its state would make sense in the case when you are changing it often, or modifying its state often. However, there are almost no cases where you want to be switching a redstone link between transmitting and receiving mode often once it is placed. Usually, it is just a hassle to have to right-click each link with a Wrench one time after they are placed to put them into receiving mode, and then never touching them again. As well as this, it is easy to mix up whether a link has been put into receiving mode yet when building in creative.

Because of the above points, it makes much more sense for redstone transmitters and receivers to be crafted into their respective forms before being placed, similarly to linear chassis and their secondary variant; i.e. place a redstone transmitter in the crafting grid to turn into into a receiver, and vice versa. This fixes the above issues.

They already have this for stress and speedometers, as well as with linear chassis and secondary linear chassis; I think it makes sense to have them as different items, since they have different functions. I'm just throwing the suggestion out since I don't know if a majority agree or not.

Also you do need to right-click with a wrench in order to change mode

making separate items seems... kinda not good. BTW, you don't need wrench to change mode

They already have this for stress and speedometers, as well as with linear chassis and secondary linear chassis; I think it makes sense to have them as different items, since they have different functions. I'm just throwing the suggestion out since I don't know if a majority agree or not.

stressometers/speedometers and primary/secondary linear chassis are different blocks because of other reasons: meters have mostly static usage cases and aren't used that often, and chassis blocks already have some wrench configurations, so devs decided to make those separate blocks and items (i guess). in case of links, you sometimes gotta need bunch of those, and craft-configuring those before starting building contraption... may be some kind of pain

Also you do need to right-click with a wrench in order to change mode

shift-right-click with empty hand on link body. have you tried that? wrench is ignored there

Sort of adjacent to this, but I feel like having the extendo grip in offhand should count as having an empty hand when right-clicking on the link, it's cumbersome to take the extendo out of off hand, to right click, to put it back in.