Replying to Has anyone tried to make their own custom footbeds, how bad an idea is it?

There are couple different websites out there that will let you buy the molding pillows for custom insoles. Seems like there is no reason you couldn't buy your own sidas or bootdoc blanks, heat them up in your oven and mold them yourself. I'm tired of going to underpaid, overworked bootfitters with lengthy turn around who don't particularly care about the work they are doing. Only 2 of the last 6 footbeds I've had made in my life have been good right off the bat, and I'm currently in the process of belt sanding and reworking the posting on my most recent set which is a long process considering I paid $200 to get them and the work is imho not great. Yes I went to someone well recommended, no I'm not going to name names. So has anyone done their own custom footbeds before? Any downsides?