Technically the tubes aren't Scoro safe, but that is because the Scoro can dump a massive amount of power in a very short time to get its super-short flash duration, or can repeatedly dump significant amounts of power into the tubes when used in the stroboscopic type modes.
There aren't any Scoro-rated tubes available for the Primo head (in fact I think the only tubes that are technically rated for it are the Pulso/Unilite tubes with the * designation), so your option is simply to not abuse the tubes if you're going to use a Primo head. If you're going to use ultra-short flash durations then keep the power to a sensible level, and be cognizant of the duty cycle if you're using strobe modes. If you keep within the Grafit A specs then you can use full power, but if you start going beyond these then you're going to want to de-rate the tubes to account for the additional abuse.
On a related note, if you're going to have to buy tubes for these then take a look at Phoxene. Their tubes are fantastic, perform every bit as consistently as the Brons, and are way cheaper to boot.
The one thing I will say about the Primo, from experience, is I don't like the fact that there isn't a locking mechanism for the modifier. You simply align the two tangs on the modifier and then rotate it, and it's this that keeps it from falling off. Not the most secure mounting mechanism by a long shot.