Two of my males have decided to eat their fins. The regrowth on one of the males fins has started growing somewhat oddly. I don't know if anyone else has any experience with this, or if it's normal, but the new growth is splitting into new rays at the points where he bit them down to. Is that odd? It looks strange. I'll try to get a pic when I get off work.

Sometimes they grow back normally and other times they grow back all weird. They probably won't look the same as they did before it happened. And keep an eye on them for fungus or bacterial infections

Add extra stress coat in your water changes to promote fin regrowth.

I don't use stress coat. Just salt and melafix. Stress coat affects the water parameters...don't think it's necessary.

how so does it affect the water per?

not at all strange, the rays are the foundation of the regrowth so in general it needs to grow first, the rest of the fins will follow once the ray is strong enough to support extra growth, suppose its like if a human was able to grow limbs back, say an arm, the shoulder and elbow would grow back first, strange way of putting it but the only way to explain it today , melafix is all thats needed, i dont use salt at all, you doing the right thing anyhow, as the fins may never be the same again but they will grow uneven for a while yet so it will look like they arent growing back ok, some bettas grow back like nothing ever happened though.

This is off the back label of my AP Stress Coat bottle: To help repair damaged skin and fins & replace slime coat add 10ml for each 10 U.S. gallons of aquarium water. In other words it says use double than what you would when treating replacement water. Might want to give it a try, won't hurt and wont affect water parameters at all, dont know where you got that from.

Jerico's fins grow back weird too, some of it grows fast other bits of it don't

yea my guy Duke had recovered from spawning with the big blue b@#$% but his fins have never been the same, he WAS a great looking ct, huge fins about a half inch for just the webing then nearly another inch just for his crowns, they were my first spawn and i let them loose for about a half hour, while i was cleaning the other tanks,, checking on them so often then bam!!!!! she chewed all his crowns off!!! now he just looks like a combtail. i am hopeing to spawn him again to try to get his dna,, cause he WAS soo pretty, its been 4 months ago and he is healthy, but not hole.