Option to tweak "DSL stability adjustment" on OpenWrt?

On my Asus DSL-N17U, there's an option to tweak the DSL "stability adjustment", which I have to basically turn all the way down to -10db to have a stable internet connection, because my connection gets some kind of spikes.
Is there a similar adjustment on OpenWRT somewhere? I have the Netgear DGN3500 DSL-modem, and it totally disconnects during these spikes, and has difficulties reconnecting.

The reason I want to go back to using the DGN3500+OpenWRT, is because of the superior QoS (don't remember what the good QoS is called on OpenWRT). With my Asus modem I get crazy ping spikes during online gaming, when someone else even loads a simple webpage.

Thank you.

At least on the BT Home Hub 5A there is an option to change the SNR margin. I don't have any legacy device and can't confirm it works there too.

All lantiq target has it . It work both ways to increase stabilyty or synchro . I'm FB7412 user.