Eb Chord Progressions: Relative Minor Substitutions

Remember from last time:

I. Eb major
ii. Fm
iii. Gm
IV. Ab major
V. Bb major
vi. Cm
vii(b5). Ddim

Each major chord in the key of Eb has a relative minor that might sound great instead of playing the major chord, and vice versa. What? In other words...

I/vi: Eb major could possibly be substituted with Cm
IV/ii: Ab major could possibly be substituted with Fm
V/iii: Bb major could possibly be substituted with Gm

Instead of playing I-V-IV-I, for instance, try the following permutations (not an exhaustive list), but we'll start with the original progression:

I-V-IV-I: Eb Bb Ab Eb
I-iii-IV-vi: Eb Gm Ab Cm
I-V-ii-I: Eb Bb Fm Eb
vi-V-IV-I: Cm Bb Ab Eb
vi-iii-ii-vi: Cm Gm Fm Cm
etc.

Substituting a major chord with its relative minor (and vice versa) might liven up a boring progression with a less boring progression (albeit still widely used).