Here is My take on it:
I would run my 2000 fxds TC 5 speed at 3000 RPM all day... No problem..
IF that is IF I used a good 20/50 fully synthetic oil in the engine. (NO syn 3 = SIN) I prefer FULLY synthetic.... Me=Redline/others=Spectro or Mobil 1 V-twin
I use a good tranny lube= Redline Shockproof Heavy---others use Spectro
Redline Primary or MTL in the clutch/chain case---others use Spectro primary
If the Oil tempurtures are Not too high like over 230* and engine remains cool at the high RPM, I would not worry about the 80/90 mph...for 30 minutes should do fine.
Oil temps of 240/285 I would Re think something .. Oil cooler? on the bike is a must.
signed....BUBBIE