Hi Christopher. If you allow.
Each webmaster should understand what the site ecosystem is. And create a site based on this.
If you use extensions based on old technologies, you should use the old template supporting these technologies. This means that Helix Ultimate is simply not suitable for the ecosystem of your site, as it contains new technologies. The RSJoomla team should strive for new technologies for its extensions.
Now you demand from the JoomShaper team to take a step back. Instead of demanding from the RSJoomla team to take a step forward.
I am a user of some extensions from RSJoomla. But I had to refuse many others there, as they use outdated code. And they do not strive to update their extensions for years unfortunately. This is a great drawback for the developer team.
Looking at the code of your site, I saw that RS Events uses Bootstrap V2.3.2.
Helix uses Bootstrap v5. These are incompatible things that cause conflicts.
RSJoomla team should make their extensions compatible with Bootstrap V5.
Or you should use template based on Bootstrap V2.3.2 / Bootstrap V3 (with some CSS coding) / Bootstrap V4 (with significant CSS coding).