GO FOR IT!!! After you mount your train-horn, post pictures!
The louder, the better, use as necessary, just don't be excessive with it, so you always have a good reason as to why you used your horn.
I have a loud 12V car horn on my bike, and use as necessary, quite often. SAVES my azz when I encounter a car getting too close for safety, and prevents folks from cutting you off.
I even have honked at a cop and waved with a smile before as a friendly gesture (and to let him know I see him, because he was riding almost beside me).
And the best reason of all for a loud horn.............PARKING LOTS!!!!! When it's one of those really busy ones, where people (and their cars) aren't watching where they are going. That horn opens their eyes REAL QUICK, lolololol!
Sometimes you HAVE to scare a few folks to SAFELY let them know you are coming, or they will just blindly walk or drive right out in front of you. I had to give a nasty continuous-horn-blast one time at a Publix Supermarket, because after stopping, and letting SEVERAL people have the right of way, immediately afterward, I got cut-off by two
cars, and 3 separate people walked right out in front of me
within a few feet,
but as soon as I laid on the horn, they all stopped in their tracks to let me by. I understand peds 100% have the right of way, but it doesn't mean they can be a dumbazz and carelessly put themselves right in front of a moving vehicle.