Which setting, 'Custom or Standard on Marantz SA-1

What setting (Custom or Standard, it can be adjusted at the back of the unit) should be used on a Marantz SA-1 SACD player when partnering it with two older Classe DR-15 amplifiers that date from 1993? The owners manual recommends that the setting be 'Standard' unless your amplifier is a next generation amplifier (whatever that means) that can support the wide playback frequency band associated with SACD. The Standard setting attenuates the ultra-high range components of SACD and makes the SA-1 safe to use with older amplifiers. They warn that using the 'Custom' setting on the SA-1 when using an older amplifier could result in damage to the speakers or the amplifier. Should I be concerned about this? Thanks.
I have a Marantz SA-14 (SACD/CD player) that is used with a 1995 vintage McCormack DNA-1 Deluxe. I switched last year to the "custom" setting and experienced nothing but improved sound. I, too, had the same apprehension about changing the filter setting. I run the CD player thru a C-J Premier LS17-2 preamp. Recently, I had the amp upgraded by SMc to the Gold Plus level. The entire system is fantastic. I don't think there should be any problem with a quality amplifier. Good luck.