First of all I know about the issue MC-108 so please don't mark it as duplicated as this issue is close as the discussion about it. I talk about this as an issue after changes of 20w18a which change the behavior of some redstone part to make it more understandable. However MC-108 and quasi connectivity was not changed however it is strange to keep it if you want to make redstone more understandable.

I understand that fixing it break a lot of redstone machine, but the changes introduces in 20w18a notably with transparent blocks broke some redstone machines too.

At least is it possible to make it the same for redstone lamp and piston & dispensers ?

The issue MC-108 as been duplicated 587 duplicated issue because this not a intuitive behaviour and was not an intended behaviour, however as the community as use this bug it has been "labeled as a feature" as MC-108 as been closed as "work as intended". I totally understand what fixing it means, so if you want to close this issue, well... I understand but please can you at least reconsider it again after change made in 20w18a ?

Also please consider that at the given time the most useful thing that this issue permit to achieve was block change, however since MC-108 observer block as been released.

Case which cause trouble:

 It is even allowed through air block ! Which is not intuitive at all ! Like this :

But not this :