So, we are looking at ~350mb of combined ram for those without dedicated videoram + some ram for codes. I guess it would be okay. Modern mid-range tablets have 1+ gb of ram, so even low-end video cards without dedicated vram should be fine. Not sure about low-end tablets with 0.5gb ram, though.
No WebGL library and cool effects in a showcase, huh. Tough guys you are. My experience with WebGL is limited by three.js and basic OpenGL knowledge, so I will hardly be useful with custom/raw WebGL codes as I never did it myself.. But, if I can get my hands on the current v2 source, I can test it with low and mid-level Android tablets just to see where it stands.