>Aside from being dangerous to the financial health of your customers, this greatly increases the chance of making mistakes in the future, since figures are made using previous figures.<

Agreed.

One possible method of dealing with that is to somehow highlight the figure as "suspect/best guess". That is how it is handled by one figure service I am familiar with.

Whenever I see any figure in "bold type" I know to take it with a grain of salt and the figure maker knows to not put much or any weight on it for future projections.

I guess you could argue either way which is better, but I prefer having the "best guess". I never bet "on" the "best guess figure", but I might avoid betting against it.