Control custom cosmetics on an ARK Ascended server

ARK: Survival Ascended custom cosmetics and gameplay mods need separate decisions. If your community wants fewer cosmetic downloads or a controlled visual environment, change the cosmetic policy without dismantling the gameplay mod list. Start by writing down the exact symptom: an unwanted cosmetic, a download delay, or a rendering problem. Those need different evidence.
Choose the scope of the change
Wildcard documents 
-DisableCustomCosmetics as a startup parameter for disabling the custom cosmetic system. Its patch notes also describe 
CosmeticWhitelistOverride in the 
[ServerSettings] section of 
GameUserSettings.ini for a custom approved-list URL. Check the current build notes before using either mechanism. A copied gameplay mod ID list is not a cosmetic policy.
For a first diagnostic trial, disabling the cosmetic system has fewer moving parts than creating and hosting an approved-list service. If you need a custom URL policy, ask support to confirm the current expected response format and reachability before deployment. Do not invent a JSON layout or point the setting at a web page containing a list of mod names.
Make a reversible cosmetic-only trial
Ask a volunteer to record the affected cosmetic, client platform and visible problem. Take screenshots that show the symptom without exposing account details.
Download the current configuration and copy the panel's startup options. Preserve the map, gameplay mod IDs, ordering and save path in your change record.
Schedule a brief restart and stop the game through the panel. Enable 
-DisableCustomCosmetics through the supported startup control. If the panel does not expose additional arguments, ask support to apply this single change.
Start the server and wait for its normal ready state. Ask the volunteer to reconnect, then check the same area and cosmetic interaction. Compare the result with the recorded symptom.
Confirm that gameplay content and the existing player character still load. Do not accept a successful process start as evidence that the intended world and gameplay mods loaded.
Separate policy from troubleshooting
If the symptom persists, capture the first relevant client or server error and restore the previous cosmetic setting for the next investigation. Disabling cosmetics cannot establish that every download or startup failure comes from a cosmetic. If the trial resolves the reported issue, tell players which visual features you intend to restrict and keep that policy alongside the server rules.
Test an approved-list policy with one allowed item and one item outside the list before inviting the group. Check client behaviour on the platforms your community uses. Avoid promising that cached client files will disappear, or that every cosmetic behaves alike after a policy change.
Roll back the setting
Stop the server, restore the recorded startup options and configuration value, then restart. Compare gameplay mod IDs once more so a cosmetic rollback does not hide a second change. Retain the original symptom report and trial result. That evidence helps support investigate a build-specific cosmetic problem without requesting a reinstall or removing content from a valued world.
Related help and sources
Choose an ARK Survival Ascended map and CurseForge mods
Investigate ARK Ascended mod updates and startup conflicts
Wildcard cosmetic configuration notes.