On-chain transfer - High transaction fees

Summary

Many users reports insanely high transaction fees when they try to transfer tokens on-chain. This is usually ascribed to high Gas costs but I thinks it's not true, but due to some bug in the smart-contract or metamask.

Steps to reproduce

Platform information

(Browser, device, system stats, screen size)

What is the current bug behavior?

What affects the high fee it's not the variable (and usually high lately) Gas Price but the "Gas Limit" which is set to 15M.

What is the expected correct behavior?

The gas limit should be set to the number of units really needed to execute the token transfer smart-contract

Relevant logs and/or screenshots

I took these screenshots in two different days, and while the gas price it's different due to its fluctuation the limit is still 15M:

Possible fixes

Check if there's a bug in the smart-contract which drives the transfer or if the bug is in Metamask there's not much Minds can do to fix other than report it to Metamask developers but in the meanwhile could be useful to tell users which is the "real" minimum amount of the "Gas limit" for the on-chain token transfer to succeed so it can be set manually. Adding Fortmatic to the wallets options could help too. Considering my last succesful transaction the Gas Limit should be around 113400 but I'm not sure