I have some (very) minor swallowing issues and I did not have a feeding tube. Almost certain my issues would be worse if I hada tube from atrophy. I know several who had a tube and have little or no issues. I guess the bottom line is to get through treatment in the best shape possible whatever it takes. If I was advising a member of my family I would urge them to try without the tube unless there was a medical reason not to.
Right now is cream gravy, ice cream and chocolate sauce. Every pound you pack on now is wiggle room later.
Good luck!!