It would be nice to see ui-testing have no dependencies on Stripes UI modules. It does so today because ui-testing is acting both as a test framework as well as the integration platform of sorts.
Tests that span multiple apps would be better kept within a platform which defines those apps under test, like folio-testing-platform. This would leave ui-testing's responsibility as a testing framework only.
The advantage of this separation is that ui-testing can then be incorporated into other tools, like Stripes-CLI without pulling down the entire app ecosystem. Further, by having platform tests kept with a platform, we can define and maintain tests that may be unique to different platforms. Organizationally, this is much like how we have app tests that are kept with each app.