“It’s a continuum.”
Is it? How many viral particles need to get thru? If you reduce them by 50%, does that do ANYTHING to prevent you from catching it? Or will the virus reproducing for another hour overwhelm that?
Had you fully read my post you would know the answer, but I’ll explain it to you.
Your body defends you from viruses all the time - you are under constant viral attack. If the invading viruses should become too numerous, you can’t keep up and you get sick - possibly opening the floodgates for other viruses.
Any defense is better than no defense, since it reduces viral load, adding to your marginal defenses. So, yes, if you reduce them by 50%, to use your number, it DOES make a difference - for anybody exposed to less than 2 times what their body could otherwise resist.
It is a continuum. Stop thinking binarily.