Based on some past & other experiences, I would say "yes' as well.
Frame up the fin in balsa (like the MDRM or an R/C plane's wing) and fill the voids with Styrofoam, then sheet with balsa.
Frame up the fin in balsa (like the MDRM or an R/C plane's wing) and fill the voids with Styrofoam, then sheet with thin ply (like, 1/16" or 1/32")
As above, and paper, or glass them, or even Monokote (that stuff can add a tremendous amount of strength!)
Use basswood sticks instead of balsa stick to frame up the fins.
Poke many many many tiny holes (pin holes) in the sheets / skins, and coat / flood with thin CA.
Use thick ply (like 1/4") and 'swiss cheese it' with many many holes (to lighten it) then sheet with balsa.
Go exotic, and make a 3-ply balsa sandwich, then vacuum bag it with either aramid, glass, or carbon fiber outer skin..
'Hot wire' cut fin cores, and then sheet with balsa or thin ply. Lightening holes can be added to eh foam cores.. Add hardwood tips & roots, LE & TE edges pieces..