Max,
Regarding researching several small projects in one season - I once had the same idea, but I don't think this is legal according to the RAW. In the ArM5 core book, the section on "Multiple Laboratory Activities" states, "If you perform arcane experimentation... any results rolled on the 'Extraordinary Results Chart' apply to all activities performed in the season." I interpret that as including the ERC roll that determines whether a magus achieves a discovery. Your saga may, of course, decide differently.
As for your intended research project, doubling the aura's effect on a magus' lab total (I think that's what you meant), doesn't sound too unbalancing to me, so I'd probably make that a minor breakthrough. You could also go for a major breakthrough and attempt to research greater philosophical alchemy from TMRE. (I'd put lesser philosophical alchemy somewhere between a minor and major breakthrough, but the OR rules are a little vague on minor virtues.)
Lastly, if you plan to be doing much original research, I commend Yair's interesting set of house rules to your troupe's consideration.
https://forum.atlas-games.com/t/insight-from-twilight-as-variant-original-research/2106/1