So this would just bypass the requirement to manufacture them first (by photosynthesis, which embryonic orchids do not have anyway).
Embryonic orchids don't have roots either to absorb the sugar from the media, so how will they get it?
Keep in mind there are a handful of other fert mixes (for adult plants) out there which add sugar.
Do they give good results by supplying the sugars to the plants or by feeding beneficial organisms that convert the sugar to nutrients for the plant?
Invitro there are no beneficial organisms.