Using Thumbs and Turbo parameters

A question I'm not sure about (just before my support subscription runs out).

If you set:

1)Thumbs to 1, to enable save thumbnails

2) Turbo to 1, to activate turbo mode

Then modify the image file with a different image(s), additional image(s) or deleted image(s) etc.

What do you need to do refresh to the new displays?

Or, should you just delete the additional files added to the file directory and let SIGE software replace with new?

Thanks
David