Then why didn't they cap it at say £200 max for a bonus buy and forbid it giving a zero paying bonus (i.e. some of the gambles such as Vikings by Blueprint)? At least with most of the bonus buys you get a guaranteed return on the investment (White Rabbit for example) unlike doing a £100 spin on any of the Netent slots where you more likely than not you lose the whole lot.
Extra chilli is a huge pain in the ass, for primarily the risk of losing your complete bonus (buy) when trying to gamble up to xx spins. It's extremely volatile. It can eat yours and 10 others budget for breakfast in an hour. I think i've seen to game change quite a few times now, where the best paying RTP is simply at those higher buys or bonus plays. And that is the cruwl part, you have to gamble to at least 16 spins to get the best out of a session.
I have tried the other BTG variants but the wagering is just time consuming. On avg 100 to 150 spins to trigger a feature, with no real guarantee that it's going to hit or not. Often i had the typical investment minus a few percent back.