I'm a novice so loathe to give advice..I did the Central Camin
ho from Ponte De Lima last year to SDC , there were some lovely stages on it - experiencing the Labruja and Coura valley between PDL and Rubiaes was lovely and also the Caldas and Padron stage.
With not a scintilla of disrespect to the route you're not going to see scenery of Swiss Alps / West of Ireland / Scotch Highlands / Rocky Mountains proportions, but you will see lovely little villages, unique churches, old Roman roadways and bridges, paths with vines growing overheads, classic historical towns like Pontevedra etc.
I am going to go back to do some of the coastal late September (last year I took a de-tour to Vigo and the route looked very pretty hence my return.
My suggestion would be to take a little time and do some research and look at some of the photos and peoples blogs of the Portugese Routes such as:
https://stingynomads.com/camino-portugues-stages/
https://stingynomads.com/portuguese-coastal-camino-stages/
https://www.pilgrimagetraveler.com/camino-portugues.html
http://caminho-portuges-da-costa.reismee.nl/fotos/
I would suggest maybe do some of the coastal and central with a walk or public transport connection between the two - there are numerous posts here giving advice on same
I hope people don't mind me posting the links above