It works with Iris. This is placed in .minecraft/libraries/me/deftware/EMC-F-v2/latest/1.21

You can follow this, but skip the installation part
https://youtu.be/rQFPvU2ew9Q?si=vyamDjX5kaKXIZHB

You should use .t IRC-Mute to disable it without it enabling after restarts.

Any fabric mod for the correct version

You have to follow the instructions for the URLs as it states that they don't work as given. The version must be replaced.

aristois doesn't support 1.21.4 forge it only supports 1.8.9 / 1.12.2 / 1.16.5 / 1.17.1 / 1.18.2 / 1.19.2-4 / 1.20 / 1.20.1 for forge version however you can use fabric instead of forge for using the latest version of aristois

No. Do you have a screenshot if the error?

Follow the instructions on that page

Thanks!