Ahah! I had it at 20 (the potency) seconds instead of 30 seconds.

30 seconds now, and it does the

HP IDC TTT HP TTT TTT HP IDC

thing now.

Code:
Starting Dragoon Simulation: Trial 0
# of Targets: 1
Boss|0	
Base Critical Chance: 12%
Recast Buffer: 100
Fight Duration: 12000
Execute Starts: 9600

[0]	: HT - Heavy Thrust - Boss -  (170)
[125]	: BFB - Blood for Blood (traited) - Boss - 
[250]	: PH - Phlebotomize - Boss -  (243.1)
[375]	: IR - Internal Release - Boss - 
[500]	: ID - Impulse Drive - Boss -  (257.4)
[625]	: PSURGE - Power Surge - Boss - 
[750]	: DE - Disembowel - Boss -  (314.6)
[875]	: JU - Jump - Boss - (Power Surge) (471.9)
[1000]	: CT - Chaos Thrust - Boss -  (377.52!)
[1125]	: LS - Leg Sweep - Boss -  (306.74!)
[1250]	: TT - True Thrust - Boss -  (235.95)
[1375]	: DFD - Dragonfire Dive - Boss -  (589.88!)
[1500]	: VT - Vorpal Thrust - Boss -  (314.6)
[1625]	: LSURGE - Life Surge - Boss - 
[1750]	: FT - Full Thrust - Boss - (Life Surge) (707.85!)
[1875]	: SSD - Spineshatter Dive - Boss -  (267.41)
[2000]	: HT - Heavy Thrust - Boss -  (267.41)
[2250]	: PH - Phlebotomize - Boss -  (205.7)
[2500]	: TT - True Thrust - Boss -  (272.25!)
[2750]	: VT - Vorpal Thrust - Boss -  (242)
[3000]	: FT - Full Thrust - Boss -  (363)
[3125]	: LS - Leg Sweep - Boss -  (157.3)
[3250]	: TT - True Thrust - Boss -  (181.5)
[3500]	: VT - Vorpal Thrust - Boss -  (242)
[3750]	: FT - Full Thrust - Boss -  (330)
[4000]	: HT - Heavy Thrust - Boss -  (187)
[4250]	: ID - Impulse Drive - Boss -  (198)
[4500]	: DE - Disembowel - Boss -  (242)
[4750]	: CT - Chaos Thrust - Boss -  (193.6)
[5000]	: PH - Phlebotomize - Boss -  (205.7)
[5125]	: JU - Jump - Boss -  (242)
[5250]	: TT - True Thrust - Boss -  (181.5)
[5375]	: LS - Leg Sweep - Boss -  (235.95!)
[5500]	: VT - Vorpal Thrust - Boss -  (242)
[5750]	: FT - Full Thrust - Boss -  (363)
[6000]	: HT - Heavy Thrust - Boss -  (308.55!)
[6250]	: TT - True Thrust - Boss -  (181.5)
[6375]	: IR - Internal Release - Boss - 
[6500]	: VT - Vorpal Thrust - Boss -  (242)
[6750]	: FT - Full Thrust - Boss -  (544.5!)
[7000]	: TT - True Thrust - Boss -  (181.5)
[7250]	: VT - Vorpal Thrust - Boss -  (363!)
[7500]	: FT - Full Thrust - Boss -  (330)
[7625]	: LS - Leg Sweep - Boss -  (143)
[7750]	: HT - Heavy Thrust - Boss -  (187)
[8000]	: PH - Phlebotomize - Boss -  (187)
[8125]	: INVIG - Invigorate - Boss - 
[8250]	: ID - Impulse Drive - Boss -  (198)
[8375]	: BFB - Blood for Blood (traited) - Boss - 
[8500]	: DE - Disembowel - Boss -  (314.6)
[8750]	: CT - Chaos Thrust - Boss -  (251.68)
[9000]	: TT - True Thrust - Boss -  (235.95)
[9125]	: JU - Jump - Boss -  (314.6)
[9250]	: VT - Vorpal Thrust - Boss -  (471.9!)
[9375]	: LSURGE - Life Surge - Boss - 
[9500]	: FT - Full Thrust - Boss - (Life Surge) (707.85!)
[9625]	: LS - Leg Sweep - Boss -  (204.49)
[9750]	: HT - Heavy Thrust - Boss -  (267.41)
[10000]	: PH - Phlebotomize - Boss -  (267.41)
[10250]	: TT - True Thrust - Boss -  (353.93!)
[10500]	: VT - Vorpal Thrust - Boss -  (363!)
[10750]	: FT - Full Thrust - Boss -  (363)
[10875]	: PSURGE - Power Surge - Boss - 
[11000]	: TT - True Thrust - Boss -  (181.5)
[11125]	: SSD - Spineshatter Dive - Boss - (Power Surge) (308.55)
[11250]	: VT - Vorpal Thrust - Boss -  (242)
[11500]	: FT - Full Thrust - Boss -  (330)
[11625]	: LS - Leg Sweep - Boss -  (143)
[11750]	: HT - Heavy Thrust - Boss -  (187)
[12000]	: PH - Phlebotomize - Boss -  (187)
Total Potency: 24804.56
TP Used: 2810
Ending TP Balance: 590
Interestingly enough even losing 10 seconds off CT only lowered dps by ~1.5%

EDIT: and to answer your question the rotation does not, simply because the offset means it will always fall off. Its clipping early before because the sim thought the attack only lasted 20 seconds, which means the "recast" thing of 4.8 seconds didn't work either >.>