WELCOME to Mayo Connect @peugh314! I see you have shared a lot of information regarding high Lipoprotein (a) here with others. From what I know, which honestly isn't much, there is no dietary or exercise program that can help with high levels of Lp (a), but there certainly are no downsides to eating a healthy diet and maintaining an active lifestyle. Lipoprotein apheresis seems like the only approved therapy. Also from what I have read, the Lp (a) test is not part of a routine lipid panel, and therefore many may have this and not know it, so I am glad you brought up some of your insights for others to think about and ask their doctor if they think it is appropriate to test for this. I think we have to be careful when we recommend supplements and such because we are not doctors here, and what is good for one may not be good for another, you know what I mean? As for the Seventh Day Adventist Diet, you certainly do not have to attend the church to find out about their dietary guidelines/restrictions, it is online in many places for others to explore. There has been a 60 year long-term study done on the SDA diet, and they show the benefits of eating clean, plant-based food.
https://www.webmd.com/diet/what-is-the-seventh-day-adventist-diet
Here is a quick read I found from WebMD regarding the SDA diet that may be helpful, and this is just one of many online articles out there. It is not a cure, as you stated, but it certainly can't hurt either! Do you have a history of any of the other risk factors? How did your doctor come to order the test for you?