Not much clue about your particular model, have I. However.... from helping others with some installs over the years and talking to pro's, I decided to keep our boat's duct scheme as simple as possible. One reason is that with the more duct work you have, the more flow/friction loss you have and the further you push the air, the more heat it loses. I know owners who said they were somewhat sorry that they spend much time and money putting in a small duct to a forward cabin or head.
Best advice, and backed up by installers, is to have a larger duct pointing into the main cabin, aimed forward away from the companionway. The moving warm air will find its way into the ends of the boat, albeit at a slower rate.
That is how we did it in our boat, altho with our aft head we did easily install a 3 foot small branch outlet for the head. That is just a lucky break for any boat with an aft head configuration.
However you do it, you will really like forced air heating.... tap an icon on a screen or push a button and you have warmth!
EDIT: I did add an engine coolant-driven small heater to our cabin, many years ago. It puts out copious amounts of heat, but of course only when the diesel is operating. The pair of 5/8" coolant hoses are indeed easier to route than an air duct. Note that all of the "hydronic" boat heaters do use a lot of power to run a separate fan for every radiator, and also have to use power to pump their heated fluid all around the boat interior. They have distinct advantages and... disadvantages.