Of course supplied TT cables are adequate*, with no need for changing - and extension best avoided.I don't understand why longer cables are a requirement. Most turntable cables are that length for a reason and better screened????
If they worked well enough to be fitted in the first instance what has come along the require this?
But in that particular club there were hum issues and much disconnection / reconnection and movement by different, non- careful DJs.
The stranded-screen bootlace cable on those decks was replaced with triple screened durable cable - and longer to avoid the need for joins.
*Having said that supplied cables are adequate....despite great care, the thin, molded stuff on my Rega arm went intermittent on one channel - that's why I fitted sockets on my Thorens.
I can understand why the OP isn't keen on his captive cables - even on the king of durable turntables.