I found your case and saw that the engineer did test the widget under ThingWorx 9.1 and found that it was not compatible with that version. Since he has already verified that information, there is no need for a new case, as the results will be the same.
However, you may contact our Sales team for engaging with one of our consultants for either modifying the existing extension available on github or creating a new extension to better meet your needs.
There is a calendar extension available on github that might work for your purposes. This is not maintained or supported by PTC, however.
You may also want to post your request on the ThingWorx Ideas forum. This will allow others on the community to vote for it which will increase it's chances of being included in a future release.