Hi im doing some filming in a large open industial unit today can you tell me how i disable the gps or what i should do to prevent the drone from flying off somewhere from loss of gps.

Just make it hover instead of going somewhere  if signal is lost and thats all you need.

main controller settings->advanced settings->remote controller signal lost set to hover.

If it simply looses GPS it won't go anywhere anyhow. it'll stay there just changing from GPS to ATTi mode.

You can't disable GPS, I wish it had that feature too.  When indoors it tends to cycle between GPS to ATTi mode depending on your proximity to windows.  Just be mindful that your not in an NFZ, a sudden GPS mode may cause you to deal with an unresponsive drone that just wants to land or hover.

Also, I think is better to start in Tripod mode,