have to complete a flying course over 3 years that could, through streaming, decide their future RAF flying career. And they compete for streaming against direct entrants who complete the course in 5 months of continuous training. Then, if they are successful, typical scheduling before, during and after IOT will leave a 1-year gap between EFT and BFT. So the first trip in a Tucano could be 1 year after the last in a Tutor, all with the benefit of 80 hours flying experience.
That was presumably why the UAS EFT course used to be 90hrs; the extra training was there to reflect the fact that it was over 3 years rather than 5 months? Why that's gone I don't know. I guess there's meant to be enough provision of IA to keep the effect of gaps in training down, but who knows?
As far as gaps between EFT and BFJT go, I personally had three and a half years between my EFT FHT and trip 1 at Linton, and it luckily didn't cause much of a snag. I can't comment if I'd have been better with less of a gap, but I'm sure some flying experience on holds helps, even if it's just in keeping you airborne.