Silencing the blower fan

You could just make sure you have nothing really close to or touching that motor. Not sure how hot it gets when running but that sort of fan is sucking air and releasing from the flexvents so there shouldnt be an airflow issue if you end up enclosing it.

EDIT: Actually it looks like that fan has some sort of vent or intake on the left hand side of the motor you would need to see if that’s sucking or pushing in air to cool the motor and then plan accordingly. If you restrict airflow to that motor vent you could hurt the lifespan of the fan or cause overheating issues.

If the noise is unbearable - there are similar fans that vent really good but are designed/advertised to be quieter then that hog lol. That thing you have just looks loud lol but at least you won’t have to worry about smoke buildup lol. Many people recommended to me the “AC Infinity - Cloudline” in-line fan and it’s pretty quiet (for a fan) in my experience.

Hopefully your venting that thing outside and not breathing in those fumes. Almost anything you cut will produce carcinogenic fumes and you don’t want to be breathing those in.