No, Optifine will never be included by default. While it does help some people, it can actually harm performance for others and it doesn't always play nice with Forge, causing rendering issues.
Plus, Optifine won't really help you too much here. Much of the load comes not from rendering but from procedural generation and chunk loading. As such what you need is FastCraft, which I'd highly recommend for any pack tbh. And, before you ask, I won't be including it either. Not because I don't want to, I would if I could. I just can't secure permissions the way Player has set them up.
It had issues with mod weapons, specifically TiCo and Quiver Bow. plus, as a personal thing, I wasn't fond of it.