Thing is though, that's an entirely logical thing for a player to do.
For example when I take a bonus I'll generally hit a higher variance slot, probably at a bigger stake than I would usually play, and if I have the luck to hit something big I'll move over to a low variance slot at modest stakes to see out WR, as I've got myself into a nice EV+ position.
If that's 'bonus abuse' in Trada's eyes then that's not a casino I'll be playing at.
In fact, I play bonuses at Jackpot Party like that all the time, and not only do they continue to send me regular bonus offers, they also send me fairly regular VIP bonus codes for bonuses that I play exactly the same way. Sometimes I win, sometimes I bust out, either way - Jackpot Party have no problem with that play style and certainly don't consider it bonus abuse because when I win they pay me without fail and with no fuss whatsoever.
I honestly can't imagine what Trada think they're doing with adding T&Cs like this to their casino, especially since the WR on the bonus is 30x, which isn't exactly a free money bonanza for the player, and is actually EV- for the player on standard 95% slots. (And quite a lot of Viaden slots are on a lower RTP than 95%.)