TL;DR:
Go to Boundless//gamescripts/sanctum and open playerstart_rerun.json
To remove the beams of light, replace that text with this:
{“scripts”:[“sanctum/default/player.json”,“sanctum/default/leader.json”]}
To remove the elder, replace the text with this:
{“scripts”:[“sanctum/default/vfx.json”, “sanctum/default/player.json”]}
To remove both the elder and the beams of light, use this:
{“scripts”:[“sanctum/default/player.json”]}