First approach:
Scale per track
64/64 with a 1/2 multiplier.
It gives you 8 bars, just that the resolution will be 8th notes instead of 16th, therefore one bar will actually be 2.
Another approach would be keeping the 64/64 steps with x1 ratio, but having every 2 bars 2 trigs at the beginning. Meaning trigs on step 1 and 2, 33 and 34, all of them with a length of 32, like so:
Trig 1: your first chord with a trig condition of 1/2.
Trig 2: micro-timing to the furthest left to align with trig 1, your 3rd chord, trig condition 2/2
Trig 33: your 2nd chord, trig condition 1/2
Trig 34: micro-timing to the furthest left to align with trig 33, your 4th chord, trig condition 2/2
That way, the first time you play the 4 bars it plays only the chords with 1/2 condition, the second time it plays the one with 2/2 conditions, and as they are micro-timed, they play as if they were on the same trigs.
Make sense?