Pendant lampholders are covered in Sec. 30-608
When you hang a fluorescent fixture from a chain that doesn't make it a pendant, it's a suspended fixture.
Flexible cord is fine, some fixtures (even hi-bays) come with flexible cord already attached.
You can even use 14awg wire taps to each fixture on a 20amp circuit. 30-412
The only thing you have to worry about with flexible cord is mechanical protection and the weight of the light not placing tension on the connections 30-400 and 30-406
The AC90 is usually attached to the chain with tywraps.
??? Round here tie-wire is used.
