Question about dw and enchant

I just wanted to ask if dual wields sub like the refine, the attack and the stability affects enchant sword or is it just my main weapon that is affecting enchant?

I chose stats str>dex but I'm not sure if agi would be better since it adds stability to sub and maybe my damage would be more stable against a boss that makes me graze and it seems most bosses on harder difficulties even with high dex I'm always grazing.
Or would sticking with dex be better since it increases my overall damage on enchant?

 

Well actually I prefer agi on dw and reaching 9k+ aspd and hiighh motion speed with 250 str rest agi

Dex hm useful but accuary is useless at some points in toram like if you already have 250 it's enough for almost everything. You'll graze anyway at nm or ulti bosses

 

Enchant Sword is a 1h skill, so it only uses your main hand sword atk, same as Blade Skills.