Minimum usable acceleration for a spacecraft

[Drashner1]

I understand but tbh I took the quote to apply in general, my inquiry was not specifically about solar sails but under 0.005 g thrust in general. But the quote does seem wrong to me, but I don't have the math to disprove it so I hope someone can

I would suggest possibly asking either:

a) on the OA Discord - someone who can do the math might be inspired to do it

b) on the ToughSF Discord - basically same reasoning as for OA but possibly more so since they seem to have a lot of technically oriented people there.

c) the folks behind Project Rho - not sure if they have a Contact Us option, but if so you could reference their page, what you see as the issue, and ask for clarification.

No guarantees for any of these, but might be worth a shot.

Todd