If you request to do so prior to travel, your ticket price will be recalculated as an open jaw TPE-AMS-HKG ticket and you will be charged the difference in fare (if any) together with a change fee and relevant taxes, as per §3.3.4 (a) of their Conditions of Carriage.
If you request to do so once travel has commenced, your ticket price will be recalculated and you will be charged the difference in fare (if any) together with a change fee and relevant taxes, as per §3.3.5 of their Conditions of Carriage.
Given the inconvenience and the possible delay to the flight by either declaring in HKG that you are not travelling further, or worse simply not showing up to board, causing them to have to offload your luggage as a security risk, you must be prepared to be penalised for not completing your travel as ticketed. If you simply "no-show" for your final HKG-TPE flight, you will eventually get your bag - but it could take some time. It's not going to be delivered to the regular carousel that all other pax on your flight from AMS collect their luggage that was labelled for delivery in HKG. They may withhold your luggage until you pay the recalculated ticket price (as per above), with potentially other fees added on top. I have no experience in this scenario with CX, but KLM specifically charges a penalty fee of €275 to have a bag returned under these circumstances. They would have charged you if you had done this the "correct" way, in advance. Therefore, do not think that if you do it the "incorrect" way that you avoid having to pay.
So the answer is that yes, you can interrupt your journey in this manner, but it will be neither straightforward, quick, or cheap, and will inconvenience yourself and other passengers.
It would be highly advisable to change the ticket in advance.
Or simply not check a bag.