There’s three actually.
Although, thinking back about it you are right, it’s not high mental stats, it’s high force. You can kick your subtle manipulations stat in the face by letting Heartbreak control your body in the mental fortitude way, then choosing to look into its eyes to sacrifice 10% of your subtle manipulations and take another 20% to will and you will be doing just as well in collecting gates.
Specifically, the three gates that require high will are, in order of appearance
“Meeting Mortum as yourself, telling her the truth (requires that your feelings are real) and then running after him.” If you have 80+ force you get a little scene where it’s mentioned how people seem to be turned away from you and the Dr. (Powers running wild)
“Shields are fraying fast” the one you know
“Hangout with Chen. He knew, and he did nothing. No, calm down, it’s not Chen’s fault.” Again, if you have 80+ force, you get a little scene where a vet fucking stabs himself with a fork, your powers are out of control and you’re too powerful for that to be safe.
And it can really help with opening gates at the auction, if you have 75+ will and telepathy upgrade you can take control of a guard to take down the security system, which will instantly leave you exhausted, and therefore allow you to open the gates easier. My favourite way to do this is
"Mayhem, total destruction. Control a guard to take down everything. Make the guards shoot at the crowd (+1 gate as long as you also have like 100 scar) I twitch as I turn to them, why aren’t they dead yet? (+1 gate high scar as well) Time to leave. Move, move, they need to Move. MOVE. (+1 gate and reveals your telepathy to Hollow Ground. Arguably a good thing if your Subtlety is really shitty because he will rely on the dampener and ignore whatever psychic intrusion may be strong enough to break through them)