I have also tried it for RebelVillage:
https://docs.google.com/spreadsheets/d/1DSNfVgpPNGrKplm7BjMBFU_mGSGYIdXRXDfx_I2rKp8/edit#gid=2147433014
Quick feedback is that it is very resistant to adding new rows into the Budget field… and any modification in it messes up with the cell formats (ie coloring), and requires people to watch out for the formulas and copy them in.
Otherwise the predicted expenses and invoicing are what we care most about…
Unfortunately the format for the speadsheet is not always the one the client sees. I made one with the format for the client and realised I have to redo it somewhere else to eliminate the unnecessary info.
Also, the client rarely sees the overhead, and so the overhead either gets included into the costs or gets renamed (i called it Project administration and accounting).