What's the reasoning behind never coming off? The amount of Test you are on won't really keep you from losing your mass as much as eating and getting proper nutrition. I have been on that dose of Test and did not get an adequate amount of protein/carbs and lost a lot of size. Diet is first then AAS
While many do stay on all the time switching from cycle to TRT dose year round - why do you want to do that though? Yeah we all love bodybuilding but don't jeopardize your health in the process. Once you get older and if any health issues arise, trust me, you won't be worrying how big your biceps are. Just be smart and stay healthy. There is no price on that. And there are ways to love bodybuilding and juice and stay healthy.
Unless you are a pro and going to make a living from it there is no reason to put yourself in that position purposely.
As far as you losing mass not working out or eating much for 16 days. Everyone is different and nobody can say how much you will lose. But it's not like you won't be able to gain it right back.