What if Lúthien had been "ugly"?

[Maédhros]

There isn't an ugly born elf, but what about elves who were captured and totured by Morgoth.

Then the heart of Finduilas was turned from Gwindor and against her will her love was given to Túrin; but Túrin did not perceive what had befallen. And being torn in heart Finduilas became sorrowful; and she grew wan and silent. But Gwindor sat in dark thought; and on a time he spoke to Finduilas, saying: 'Daughter of the house of Finarfin, let no grief lie between us; for though Morgoth has laid my life in ruin, you still I love.

I wonder if Findulias stopped loving Gwindor, then is it not possible that Beren could not have loved Lúthien if she were not as beautiful as she was?