GIB stumbled into an impregnable game here but I despise the sequence.
Once again I plead for GIB to start playing something simpler (and better IMO) like Landy.
-- should 2H take precedence over 2d showing majors with this shape? Part of the problem is GIB says 2d is 5+/5+ majors and 2M can be 4/5 either way which is ugly and unplayable IMO. I'd rather be able to bid majors on 5-4 (partner has an ugly guess with equal length and 3/3 or 2/2 majors, but that's the breaks with capp), but I don't mind that much when at least both your suits are known.
If insist on keeping capp, IMO
2d= 9+cds in majors, 4+/4+
2M should promise 5M not 4M like it does now. This makes it easier when partner has like 4243 type hand can pass a 5-2 heart fit. And makes inviting major games easier.
3m in response to 2M should be something like 1-M, 6+m at least, not 3-M 4+m (!!!!), and not show 14+ total points. It should just be improving partial with misfit.
With actual hand above it can bid 2nt, which should be either 4+/4+ in minor, 2-H any strength, or 10+ with 3+H inv, overcaller shows minor then advancer can pass/invite/bid game as appropriate.