Write to support@kuules.com. It is one person, so it may not be instant, but it will be answered.
SmartScreen shows "Windows protected your PC" for new releases until enough people have installed them. Click More info, then Run anyway. The installer is signed by Calm Base Oy — you can check by right-clicking it, Properties, Digital Signatures.
Most hosts only scan for new plugins at startup, so restart it first. If they are still missing, check the plugin paths in your host's preferences include the standard VST3 and CLAP folders. Some hosts keep a separate blocklist of plugins that failed a previous scan — worth clearing.
Not yet. It is planned, and there is no date. Windows only for now.
An ambisonic field of order N needs (N+1)² channels: 4 for first order, 16 for third, 121 for tenth. VST3 stops at 7th order, so use the CLAP version above that. Your track must be wide enough or the upper channels are simply not there.
That is what X-ray is for — insert it either side of the plugin you suspect and it will show you what actually changed. Failing that, email with the plugin, your host, and what you expected.