Every battery will degrades eventually. Just enjoy the fast charging normally as nowdays all charger are efficient & smart will auto disconnect but be sure use top notch brand such as your aukey.

Once you start fast charging you will not go back to cute little 5watts. Same as wireless charging since I started to use wireless charging its very convenient and my battery ready to go anytime unless need extra juice of power ASAP.

Just be sure your ip not overly heating up such as your case are too bulky/less heat dissipation.

I believe the new batteries supporting fast charge may withstand degradation a little better. Otherwise the public already put out bad reviews on battery life after some uses. My phone has similar fast charge feature. So far, after 1+ year usage, battery life seems almost no different from new... so acceptable for me.

been using fast charging since Dec 2017 and still using. iPhone X battery health currently at 81%

Yes bro. 81% for 3 years quite good. Been gaming alot past 2 years but still good.

I have not experienced any throttling. Everything smooth as usual. Im thinking of change battery after Raya. Seems like my phone can still be use for another year or two.