You can make changes to presentations that you embedded fonts into with the Editable embedding method, as long as you re-embed the fonts after saving the changes.
This is because versions of PowerPoint other than the one for Windows can open presentations that have fonts embedded, but they ignore those fonts and they do not keep them in the presentation file when saving changes. It is therefore recommended that you wait and embed fonts into your presentations when you are done working on them, or before sending to colleagues for review.
If you make the changes on a PC however, you do not have to embed the fonts again. The Windows version of PowerPoint will keep the fonts embedded in the presentation after making changes unless specifically instructed not to by changing the saving options. Note that some fonts do not permit making changes to the documents they are embedded into. If you used such a font then the Windows PowerPoint will prompt you to remove it before making changes, and you will have to re-embed it even though you made the changes on a PC.