If ballast was available in an official patch within say 1 week of the start of the series, then i'd be willing to see that added, i'd be neither in favour or against it being added really, i think partly its hard to justify slowing the fastest person down just because they're the fastest, but i also understand the part it can play in having a close series.
The key thing for me would be that we only used what was official, and for a series which lasts exactly 1 month i'd also suggest that we used the same patch from start to finish. ie Patch W (or what was current within a reasonable timeframe before the series started) purely in the interest of keeping everything equal. LFS takes up little space, i'd bet >75% of the HD space LFS uses is skins, install a specific version purely for use in this series, that way if mid-May Patch X is released with a whole host of features the series stays the same, just as it would in real life (ie things rarely change midway through a series, traction control isnt suddenly allowed).
Ballast, i'll be happy with whatever popular opinion says (leaning more towards none, but no strong opinions on the matter) provided it wasnt done via test patches, just because new ones come along every other day and as the name suggests they're just test patches, the current has problems kicking people to spectator for doing nothing, so my only reservation would be in having Ballast via a test patch.