Yep, that tin is clever—except you can't see all the main transpositions at once, you keep having to turn the whole doodad around. This is a case in which I'd use the fifths order instead, since then the main chords would all cluster on one side of the doodad, in the order 4 1 5 2 6 3 7 (or for minors, b6 b3 b7 4 1 5 2)—so you'd also have a means for quickly determining the relative degree for each chord, in either source or destination key. To make this even easier, you might cut out a cardboard circle with these degree numbers around the edge. You could store the circle in the tin, and when you needed the degrees, you could pop it on top of the tin, aligned appropriately. (Actually, if the tin has a slight bulge on the top, as appears to be the case in your picture, and as some similar tea sampler tins have, you might want to mark the tin with the bottom up. The flat bottom would help keep the cardboard circle in place, and the bulged top would provide a pivot for turning the tin around.)
To simplify presentation with chromatic order, I might represent the accidental intervals with just big dots, which would favor neither flats nor sharps; the appropriate names are clear from the neighboring letters (and the side on which they lie). This might also let you fit the chromatic order around twice, so from one side you could see almost an entire chromatic sequence, and thus avoid having to turn the tin.
For transpositions, I often use simple fretboard patterns, combined with a root-centric view of the chord shapes. Trying to figure with pitch names or referring to separate cribs is far less efficient than just envisioning patterns directly on the fretboard. The fourths/fifths pattern is one I rely heavily on in normal play in any key, and covers two of the most common transposition needs (incidentally, also the chord name/shape mappings between C and G tunings). Transpositions by a half or whole step up or down are relatively trivial to handle in my head (another four keys). Combining fourths/fifths with half-steps, I could cover three more transpositions (up/down by major thirds or tritones), though I'm more inclined to use the augmented shape (n:2110) and a handful of tritone offsets for these keys instead. That just leaves transpositions by minor thirds, which correspond to the dim7 shape (though less intuitively than the aug or tritone shapes).
I sometimes use a couple of other transposition approaches, but their description would probably glaze your eyes. Nevertheless, they work quite efficiently when you're accustomed to playing by relative patterns, as I do almost exclusively these days. I find lead sheets with fixed chord names a pain to deal with, since I nearly always have to transpose them, and by a different offset for each song.