Genuinely curious, is there a way of tuning how this protection is triggered? If there is, perhaps filter out those ISPs/countries from which most attack originate? Not a cloudflare user myself -- for me it's mostly been a nuisance.

I use cloudflare and I block whole countries because the bots and spam are so bad from places like Singapore.

Cloudflare makes region blocking very easy.

At least to me, cloudflare has never shown any fine tuning options.

Cloudflare offers more options to paid customers than to free customers, but with basic Cloudflare Rules you can usually configure your firewall and presents to your liking.