There's no way a person can detect that you're using Vape's aim assist. I guess the only way is if you are using a way too high FOV like 360 so your head is going to spin way too much. And don't worry about Watchdog, it can't detect. I think you should keep your FOV at MAX 110 or 180.
I have no idea why people here find hitboxes so risky. In the past I used for weeks on free clients and cracked vape and I was not banned. I don't know if Hypixel now detects, i'll try to play with 0.25/0.3 in a alt for a week and check the results.