Follow up: How to make zen mode background/backdrop actually the same as current buffer?

[mathisi]

This question can be considered a follow-up to this, which was also about making the background of zen mode the same color as the current buffer but without any transparency.

The proposed solution is something like the following:

win = { backdrop = { transparent = false, blend = 99 } },

However, with that (at least in my case) the backdrop still slightly varies from the color I am looking for. Obviously, setting blend = 100 should result in the correct color; however, with that, transparent=false is dismissed and the text in the backdrop is again shown.

Proposed solution (the color difference is very subtle but certainly there):

Actual behavior for blend = 100:

Behavior I would consider intuitive:

Looking around the codebase, I found this line, which seems to be accountable for this behavior. In my (purely user-based) opinion, the described behavior is buggy and shouldn’t be like that. However, as this line or backdrop.blend == 100 is explicitly written here, I suspect this behavior is intended, in which case I would be interested in the reason.