If anyone is still trying to get test mode to work with drupal 7 and Stripe Checkout, I was able to get that to work by just adding $this->fixPaymentProcessorID(); to the end of wf_crm_webform_postprocess::fillDataFromSubmission().
I don't know how to answer the question about how the tag used to get created or why it didn't get created, but I've pushed the 6.2.5 tag to github: https://github.com/colemanw/webform_civicrm/tags
It's close but there's still some moving parts.
One thing is you'll need to use the unreleased 6.2 branch for the parent webform module.
Then there's a branch of webform_civicrm that works but it's not ready to be merged back yet. You can install it with git to get around the composer problem, or set up a vcs repo in the repositories section in your root composer.json, but I only recommend that for a test site since such things tend to be forgotten to be removed later and then cause problems.
There are some other 3rd party dependencies still outstanding if you use it for contributions.