I ran a lengthy test to primarily check if 2t11 actually works on Pyroblast! on the way I also collected some more information on T3 Hot Streak, T4 HS wasn't selected, MA wasn't used and Critical Mass was on the target, P! glyph wasn't used;
l85 vs l85 dummy
Character crit rate: 21.28%
Scorch: 15301 casts, 4169 crits (27.247% vs. expected of 21.28 + 5 = 26.28%)
Pyroblast!: 1363 casts, 423 crits (31.034% vs. expected of 21.28 + 5 + 5 = 31.28%)
Pyroblast! ticks: 5487 ticks, 1689 crits (30.782% vs expected of 31.28%)
Hot Streak procs: 1426 (34.20% proc chance, at the crit rate of 21.28 (CM isn't taken into account))
As a conclusion 2t11 does in fact work for Pyroblast! and we have one more data point for T3 HS function. I hope to rerun the test in a few days with 2t11 + Glyph of Pyroblast! and a much higher crit rate (circa 32% I hope).