Hi Damian,
Great to see your paclet on the repository! :)
The reason the PacletInstall[..] command did not work is that there is currently a bug causing a delay of at most 1-2 hours between the paclet becoming visible on the repository website and the paclet appearing in the PacletSite metadata file that the PacletInstall[..] command checks to know about available paclets.
A bug fix for that is in the works (so that a published paclet becomes visible to PacletInstall as soon as it is visible on the website), and will go out when we do our next resource system infrastructure update in the next few weeks.
In the meantime, the PacletInstall[..] command should work now because the PacletSite file has been refreshed since then. I was able to install your paclet successfully.
Thanks,
Connor