05-01-2017, 04:15 PM
The cross-section of SDK features your test plugin utilized simply might not have intersected with the features that are incompatible across Illustrator versions.
While compatibility can sometimes be maintained between Ai versions, we have found it to be too unreliable and subject to too much change (from Adobe). For example, Ai 15->16 broke all kinds of things, 18->19 had a few broken things, and we've heard from little birdies that 21->22 will break some things too.
In short, the best way to maximize reliability is to break out each major version of Illustrator as a separate compilation target.
While compatibility can sometimes be maintained between Ai versions, we have found it to be too unreliable and subject to too much change (from Adobe). For example, Ai 15->16 broke all kinds of things, 18->19 had a few broken things, and we've heard from little birdies that 21->22 will break some things too.
In short, the best way to maximize reliability is to break out each major version of Illustrator as a separate compilation target.