stretching PA piercing 4ga to 2ga

would like to ask the community who is familiar with this:

I've been with PA for 7 years, 4ga the whole time.
I've been looking to upgrade my device. I've been quite happy with the evotionchastity.com orion and want to order again. They offer a hollow titanium PA pin starting with 2ga. Size.
I am intrigued by the possibility of a cleaner stream for urine and wonder if this is indeed the case?

Another question is how much effort would it be to insert a 2ga in my fairly loose 4ga without using a taper?

Also in your opinion would a hollow pin expose me to a higher risk of a UTI if I am frequently in the ocean water that now can get deeper into the urethra?