Action Bar highlighting is my favorite feature of Hekili. Other addons (e.g. WeakAuras, MaxDPS) take advantage of LibCustomGlow to expand the functionality and customization of button glows, including texture overlays. Any chance this could get integrated into Hekili?

SpellFlashCore is in Public Domain, you can use any of currently working fork of it (eg from here).

Closing, as the addon has allowed customizing the SpellFlash glow for a long time. I have no plans to make use of LibCustomGlow.

To be clear, what you want is for the SpellFlash feature to have more customization options? I can take a look.

Exactly, thank you, I really appreciate it. I've tried MaxDPS addon in the past but I much prefer Hekili. The only thing I really liked from MaxDPS was the action bar customization. By default its a circle (Interface\Cooldowns\ping4), but could be changed to the glows like SpellFlash or Blizzard. I stumbled across the library after digging around in my addons folder, particularly weakauras2 (who's author contributes to LibCustomGlow). Seeing as SpellFlash isn't maintained anymore, I figured LibCustomGlow may be something you'd be interested in exploring.

I've used LibCustomGlow (and it is packaged with the addon). However, the SpellFlash library is what locates abilities on your action bars and starts/stops the flash effect. I'll see if it's relatively trivial to use it to use LibCustomGlow flashes instead of its default.

Please please :). Custom Texture would be perfect

It's still an okay idea, just not at the top of my priority list.

anyway to make the flash more noticeable? Spell flash hasn't been updated in 2yrs. It's VERY subtle

Not a priority at this time.

@Hekili ok.. I know at least 2 people who will stop using hekili because of it.
for me, I like hekili just need to figure out the druid issue.

This would be a feature I would use as well, FWIW.