Honestly that would be too easy, but it would be nice if that would work. The only thing is that the pre created would have to be accountbound or else the precursor market would probably crash quite a bit.. which may not be such a bad thing. I have heard though that if pres were easier to obtain, T6 mats would raise in price as they are complements in production of a legendary.
And wouldn’t making it this way only cost you 5 laurels since you can reuse the recipe for say an ascended dagger? And the cost in terms of vision crystals seems relatively neglibible since those mats just pile up. I don’t know for sure though since I’m not making ascended weapons until after I finish my first legendary in a few weeks of dungeoneering.
And as for “what you are missing”, I don’t think an easy interim solution would be good for the game, as I’ve said it has grievous economic implications for related markets, and its unhealthy to do that to a game. I understand the RNG is frustrating, but I find it helpful to avoid thinking of it as RNG. If you do that, then you might as well think of the game as a whole is just a load of RNG.
I find it more frustrating that precursor costs are so variable over time, and that rich players are able to profit by flipping them. I’d rather have a high and constant cost gold cost per precursor than have to deal with flippers causing a 100 gold spike in price that lasts for months for no apparent reason. I can calculate how much gold I can make in day which will help me set a timeframe for my goals (usually 25 gw2 gold per day if I can squeeze in all of the easy dungeons and salvage stuff, which gets frustrating doing day after day).