BSV is not a fork of BTC.
The funny thing is that you are not even wrong about that. BTC is a fork of Bitcoin.
Then where is the original? A "fork" implies an offshoot was made while the original continued onward.
BCH = hard fork
BSV = hard fork of hard fork
BTC = soft forks only
Satoshi-era builds are somewhat compatible with today's Bitcoin network. However, they are zero percent compatible with BCH and BSV networks.
One could argue that BSV is a fork of Bitcoin as well.
They could argue that but they would be wrong in every aspect.
However, it is the only such that has forked itself back into near compliance with the original definition (i.e. the definitive definition) of the Bitcoin protocol.
This is simply a tired talking point with no technical basis. Looking at the current BSV GitHub repository:
gmaxwell - 144 commits
deadalnix (Sechet) - 766 commits
sepa (Wuille) - 835 commits
Your coin was largely built by Blockstream and Bitcoin Cash devs, and it remains that way.
"BSV is set in stone, until we change it, again."
And you again demonstrate your abysmal ignorance to the fact that a protocol is not the same thing as a software implementation. You seem to parrot this inanity at every opportunity, heaping yet another pile of rightful derision upon your ignorant ass. One might expect that a person with a modicum of intelligence, having this gaping hole in their knowledge pointed out to them repeatedly, would pause to actually learn something about the matter. But no. Not you. No, not you.
FWIW, BTC has indeed endured a hard fork - though it was back in the time before BTC, BCH, and then BSV each went their own respective directions. So it is irrelevant as a differentiator. But you still want to cling to 'soft forks only', don't you? Demonstrating yet another vector of your ignorance.