Breakneck Speed Multiplier to match Expert track speed on Hard?

I was wondering if anyone here knows, offhand, what Breakneck Speed Multiplier setting I could use while playing on Hard that will approximately match the track speed of Expert?

I normally play on Expert, but for longer band play-sessions (when wrist fatigue is setting in) and tougher songs I'm not really familiar with, I'd rather drop down to Hard for the sake of overall group enjoyment... but then the problem is that the lower track speed really throws me off and takes me a bit to readjust... and, by that point, I've missed enough notes to feel like I might as well have just stayed on Expert, anyways.

But, now that we have a variable Breakneck Speed Multiplier setting, I should be able to approximate the same track speed as Expert when playing on Hard.

I tried a couple different settings, myself, but it was too subjective to tell which setting was closest. (I couldn't tell if each one seemed better/worse because I was just getting used to the different speed of the last setting or what...)

It would probably be easier to figure out what it is with two guitars, turning on the independent track speeds, and trying a few different settings to see which one matches the speed of Expert the closest... but I only have one guitar... so maybe one of you kind souls, out there, that has two guitars could do a quick experiment for me?

^((And whoever does may just earn themselves the Reddit equivalent of Gold Stars... ;)^) ^)