You are correct, FAP17 (Adjustment depreciation, cost accounting) & FAP18 (Adjustment depreciation, balance accounting) are available in IFS APP8; and not in IFS APP10. 

However I found several solutions where R&D explains, “Posting types FAP17 and FAP18 were not used anywhere in the application. Those posting controls were introduced some years back and the supporting functionality was never implemented in the application. That is the reason why it is not possible to define any control types for the mentioned posting types (besides AC1). It will not affect any fixed asset flows since those posting controls are not used.”

Therefore in APP10, R&D removed FAP17 & FAP18 posting controls.  To see all the posting controls available for Fixed Assets in APP10, navigate to ‘Fixed Assets Posting Types’ screen and populate.