Capes VS phosphor-fabric

Sadly no. BUT there is a client side mod called capes which let's players have custom capes but you have to have the mod to see other players custom capes

After a quick search I found this mod called Fabric Capes, which might be what they're talking about

Fabric Capes (by VictorKohler)

You can install Kappa or Fabric Capes alongside sodium/iris for optifine capes

You can replace all of Optifine's features with the right Fabric mods, like Continuity, CEM, Animatica, FabricCapes, and Iris. I don't know all the features Optifine has, but every important feature Optifine has that I can think of has a Fabric mod counterpart.

Well, there is the Fabric Capes mod, it shows capes from OptiFine and a whole bunch of other mods

you can get to see your capes in fabric, just add this mod https://www.curseforge.com/minecraft/mc-mods/capes :)

Phosphor (another optimization mod by the Sodium devs, targeting the built-in lighting system)

Sodium Phosphor Lithium also get iris but I don't have download link

There’s lots of lightweight shader packs designed for low-end PCs. For an optimized, smooth shader experience I’d recommend installing Fabric, Sodium, Lithium, Phosphor, and Iris Shaders.

I would suggest you to use Sodium or Iris - Overall Performance Improvement / Iris If You Wanna Use Shaders Too Lithium - Improve CPU Usage LazyDFU - Launch Game Faster Phosphor - Improve Light Engine Hydrogen - Reduce Memory Usage

Low performance is to be expected with your config. You can try to install these performance mods for minecraft : * Iris that contains Sodium * Sodium, don't use it with iris, it already has sodium. * Lithium * Phosphor

Lithium is only for Fabric. There's also Phosphor to improve lighting performance.

You can get better performance and retain vanilla features by using Fabric with phosphor and lithium.

for newer versions Sodium+Lithium+Phosphor (+aditionally hydrogen)

Please use the Randon World Format for it uses less RAM and uses less file space and please use the Lithium Lighting Engine for the same reason.