Barriers and light blocks display dedicated particles when their item form is held as to show the location of the blocks, due to them usually being invisible. These generated particles, however, are flawed in two ways:

• Rather than just generate one particle per block, they appear to generate multiple particles instead, which can be seen in the particles menu especially in an environment with no other particles. This does not result in any visual differences, but the game having to render extra particles impacts performance especially when a lot of barriers/light blocks are present. (MC-238261)
• The particles do not appear immediately when the item is held or the block is placed, nor do they disappear immediately when the item is switched away from or the block is broken. (MC-47660)

With the first issue being a performance bug and the latter issue being somewhat of a visual bug, I feel as though fixing this is something Sodium would be completely suited for.

In addition, no particles appear if the respective item is held in the offhand.

There is a particularly obnoxious side effect of this issue as of 21w42a: https://bugs.mojang.com/browse/MC-239399