Yes, I share the same opinion that every item in the signal path affects it, eventhough Adrian from Afterdark told me it won't.You need a minimum loss matching pad to connect 75<-->50 ohm. They aren't perfect as you will get a loss of 5.7dB across the pad which is 4x less power on its output. Plus limiting bandwidth and small amount of standing waves. But is better than connecting the mismatch directly.
Something like this...
https://www.ebay.com/itm/362592867596?hash=item546c38150c:g:Y2YAAOSwh7tcRFs0
So, if a cheap clock, plus a cheap LP, plus a cheap BNC cable, plus the impedance adapter betters the sound of the ER, a good master clock with double output with different impedance will be a bliss!!