I don’t know how you were taught to deal with an engine failure after V1, but most pilots take no action, apart from flying the aircraft, until above a safe height, for the 146, 400 ft. The retardant can be jettisoned in 3 seconds with no change of trim to the aircraft well before reaching that height. This exercise is practised regularlyin the Simulator without difficulty. Also, you are right that a qualified pilot should not have any difficulty abandoning the take of prior to V1 (however, you do not reject from V1 as you stated, once V1 has been reached you have to continue take-off). However, with the Fire Fighting 146 (referred to as a Tanker) fully loaded on a limiting runway the potential for damage may be greater stopping than getting Airborne and then significantly reducing the load. The BAe146 at a weight of 28,000 kg will climb away quite comfortably on 2 engines and this would be the weight after jettisoning the retardant.