Computer Configuration > Administrative Templates > Microsoft Edge
Both
HKLM\Software\Policies\Microsoft\Edge
OBSOLETE: This policy is obsolete and doesn't work after Microsoft Edge 123. Throttling of cross-origin frames that are display:none and non-visible is a feature designed to make cross-process and same-process cross-origin iframes consistent in their rendering behavior. For more details on cross-process vs. same-process throttling, refer to https://go.microsoft.com/fwlink/?linkid=2239564. This enterprise policy exists to allow administrators to control whether their users are able to turn the additional throttling on or not. If you enable or don't configure this policy, users can opt-in to throttling. If you disable this policy, users can't enable throttling.