900 LED (3 x 5m WS2815) infinity mirror build - planning phase questions

Thanks for your comments. Sounds like I am on the right track so far. What kind of 'noise' would one expect in this scenario? I see some mention of no resistors, or lower values being used.

Should I start with no resistor and see what happens? I just don't know what to expect for noise and I would hate to jump right in and add a resistor, if its not needed.