I have replaced the sparkplug at 28,000 miles on all my spyders (2014RTL, 2015 F3S, 2018 F3L, 2020 RTL, 2021 STS) and not one of those needed it. I have replaced them after 35,000 miles on my 2020 RTL and the plugs still looked great. I am now waiting until they have 50,000 miles before changing them to see how they are. That will be at 115,000 miles on my 2020 RTL (currently at 92,000 miles). My wife's 2021 STS will hit the 50,000 miles on her sparkplugs in about 7,000 miles. Plugs changed at 28,000 miles and she has around 71,000 miles on her spyder.
So my advice is don't replace them at 28,000 miles, but do replace the motor oil, oil filter, transmission filter, and fuel filter.