The main issue is all about liquidity, so there is a requirement for all crypto exchanges to solve this at the first place. GBP pairs are the volatile exotic spot forex pairs which can move more than %8 in a day. Imagine merging the volatile crypto pairs with it and the liquidity will be at the lower levels along with the huge spread. For example, GBP/JPY pair is the most volatile forex pair and that is why many traders avoid to risk more than 1% in single trade with exotic pairs. The similar situation is case for volatile GBP/altcoin pairs.
Do GBP currency will really have that kind of percentage volatility in a day? 8%? For fiat movement then im not really believing this much since fiat wont really he moving on a very large scale in 24 hours.
Also im not really that convinced on comparing fiat/fiat to fiat/crypto pairs because it is entirely different.In topic reply then price rise differences will really depend on liquidity on each platform
where it do involved volume and activity inside the platform.So you would definitely see different percentages but on a very minimal gaps.