Right now metamask fees user interface is really garbage which is a shame that leads people intentionally loosing thousands of dollars . Metamask is a wallet that want itself easy to use so beeing accessible to everyone while not preventing user to mistake regarding high transaction cost is a serious misconduct that could be brought to justice depending on the country.
→ Limit in network fees should be printed in evidence on the first page of the transaction (not after the loading to estimate the fees, from a user perspective estimated fees is garbage).
→ The default limit should by default be set to a tolerable margin regarding the global transaction (~2%).
→ If required network fees to have chance to execute the transaction is superior to the default or user limit, a yellow warning could occurs to indicate the user that his transaction is not likely to be executed at such low fees. ( and indicate the estimated fees to have it executed in within a short time range).
→ If the user manually change the max network fees to something higher than 2% of the transaction, a red warning should be present at each confirmation steps to remind him the transaction fees (and setting this max above 2% of the transaction value should only be doable by the user itself).