yes, SE is Special Endurance and you are right about the probable percent. The difficulty with squats to parallel for comparison is that if the weight gets near max, it’s pretty likely the squat will be less deep and therefor will go higher but it’s not a true comparison. As an example, Milt Ottey, (World no1 HJ in 1982) was well above 700 but quite shallow as this is more appropriate for his event which is not back dominant.