The guys I have known who have done this have needed some "career repair" following their time at Formation Recce. You will be out of the RE reporting loop at quite a critical time in your career, and you will doing a job that the cav are happy doing without you. I think the whole thing is engineer empire building and unnecessary. Do something else instead!
I can tell you now mate, DO NOT apply for this job... You will get f**ked over by the Corps and records. Ive been in post for 2 and half years already, and records reckon they will extend me till 2011, thats 4 and half years outside the corps. No one gives a f**k about you, so you have no complaints system, you get empty promises from everyone from the EinC down.
No kit, No job and no F**king career!!!!
Nice one the Royal Engineers, you now have another bitter SNCO!