Interesting.
This game seems to run on 9-6 double double bonus, which is normally a 98.98% game. This returns 99.01%, so as far as overall return goes, it's about neutral.
But yes, this induces a shit ton of extra variance.
According to Wizard of Odds, this multiplier hits 11% of the time. What is the game's return on the other 89% of hands which don't get a multiplier? 31.4.%. That's right -- 31 fucking percent. Ouch.
So you're absolutely going to get beat down on the hands with no multiplier, and it basically becomes a combination of a luckfest to get multipliers more than the 11% average, combined with getting to high multipliers and being dealt a good hand, combined with making correct decisions regarding when to accept or reject the multipliers.
Here's what Shackleford wrote about accepting multipliers:
This can be a pain in the ass to calculate sometimes, because you're figuring out your EV after the deal. As far as dealt pat hands, here is the minimum you need to accept each of these multipliers:
2x: Full house or better
4x: Flush or better
5x: 3-of-a-kind or better
8x: 3-of-a-kind or better
However, you also need to compute your EV for non-made hands. You really only need to be concerned with this for big hands which need 1 card to hit.
4-to-a-royal's EV is 18.
4-to-a-straight-flush EV is 3.53.
Dealt three of a kind is a bit more complicated because of the different pays for hitting quads, and quads with kicker. So that means anything A-4 trips is definitely worth keeping for 3x multiplier, and 5-K is probably marginal. I haven't figured out the exact EV.
Anyway this game has a ton of variance, so you should play much lower than you are accustomed to, or otherwise you might lose a lot of money really fast.