This maximum speed is the speed of light

It is just a dogmatic and completely unproven assumption that was needed for Einstein to keep his relativity consistent. Nothing in math and physics could be a reason even to assume that such limitation exists.

Moreover, in case of signal transmission speed, that statement was disproven by Gunter Nimtz and replication of his group experiments. Tunneling speed is much higher than speed of light.

Speed of light is just a speed of electromagnetic waves in vacuum. Just like speed of sound in standard air conditions, nothing more. It is even describe more properties of vacuum, not electromagnetic wave itself. It is well proven, than speed of electromagnetic waves in more dense media is lower than speed of light in vacuum, so speed of light definitely depends on media. And potentially, speed of light will be higher than that "constant" in a media less dense than vacuum. If you think that there can't be a media less dense than vacuum, you are already wrong - Casimir cavity effect proves that there could be things less dense than vacuum. However, for some unknown reason, studying of Casimir effect is very unwelcomed in official science, so nobody measured speed of light in Casimir cavity yet.

So, the conclusions in article made on base of false dogma is just wrong.

This maximum speed is the speed of light

It is just a dogmatic and completely unproven assumption that was needed for Einstein to keep his relativity consistent. Nothing in math and physics could be a reason even to assume than such limitation exists.

Moreover, in case of signal transmission speed, that statement was disproven by Gunter Nimtz and replication of his group experiments. Tunneling speed is much higher than speed of light.

Speed of light is just a speed of electromagnetic waves in vacuum. Just like speed of sound in standard air conditions, nothing more. It is even describe more properties of vacuum, not electromagnetic wave itself. It is well proven, than speed of electromagnetic waves in more dense media is lower than speed of light in vacuum, so speed of light definitely depends on media. And potentially, speed of light will be higher than that "constant" in a media less dense than vacuum. If you think that there can't be a media less dense than vacuum, you are already wrong - Casimir cavity effect proves that there could be things less dense than vacuum. However, for some unknown reason, studying of Casimir effect is very unwelcomed in official science, so nobody measured speed of light in Casimir cavity yet.

So, the conclusions in article made on base of false dogma is just wrong.