I reckon that Stefan GP should be allowed in- one thing that could help them and another team who are struggling the most financially is that they are only allowed one car on the grid, at least then they are still getting on the grid and developing the car and able to fulfil sponsorship deals, etc.
End of the season, if either teams make it through to the end and can prove they're financially sound for the following season, give them full privileges.
End of the day, it'll be nice to have a bigger grid, means more battles and possible upsets, more interesting races as there will be more cars for the front markers to lap which can usually create drama and shows how good the leading drivers are.
I still remember back in the early-mid 90s where there were massive grids, I know that the likes of the Forti team and Minardi who were massively off the pace but did blood some of the top drivers such as fisi, badoer, del la rosa, etc just to name a few off the top of my head.