Sounds and letters

I wanted to ask something. I found a band logo today for a korean band that pronounced their name as "beast" but the logo was "B2ST". I spent a ridiculous amount of time staring at it trying to make sense of it, turning it this way and that, distorting "two", but my puzzlement only grew. Until my dear friend pointed out that the 2 could be in the band's native language. I'd already thought about that but dismissed it because two in korean is "set" and in their chinese loan numbers "ii".
When she said it though, I realized that "ii" and "ea" in beast probably is the same sound. I say probably, because in my head, it's not. If you recorded me saying the two sounds, I realize that I'm very unlikely to hear any difference myself, but would you ask me when I'm saying it, I'd swear that I'm saying two different things. In my head, when I say or hear "beast" there is clearly both an "e" and an "a" in there. I feel them... it's not quite seeing and not quite hearing.
This probably helps me with spelling, because I would also claim that I can "hear" how a word is spelled (probably it's just obscure grammatical rules that I've somehow absorbed subconsciously, and I'll claim the same even if I spelled it wrong the first time and then learned the right). But it does confuse me when it comes to word-plays like the band name.

So the question is, do you too?