Sure thing:
p.125 R&G
[spoiler=RUN FOR YOUR LIFE/ DIVE ON THE GRENADE]Interrupt Action (–5 Initiative Score)
[...] Immediately after a Throwing Weapons Attack or Area-Effect Indirect Combat Spell Spellcasting Test, a character can make an immediate Interrupt Action to flee. The character chooses a direction to move and can use any amount of available Movement to move away from the incoming attack. (Note that the gamemaster is not obligated to determine or declare the final location of the attack in the case of a fleeing character. A bad
bounce can still get a grenade on the character’s tail.) [/spoiler]
Technically, you'd have a point to not allow me to use "run for your life" since it's neither a throwing weapon nor AoE spell.
Soak roll:
Soak:
24d6t5 11 [24d6t5=3, 3, 6, 4, 6, 6, 1, 6, 2, 5, 6, 6, 5, 3, 5, 2, 6, 3, 4, 4, 3, 3, 5, 4]
It would explode 1m away from Isaint (him being roughly 2m high), incuring him 3S after soak
SInce I already used my free action this round, I could drop prone with "hit the dirt" p.168 core and reduce my height by another meter for only 1S, bringing my total up to 3S
[spoiler=HIT THE DIRT](–5 initiative score)
A character who has already used their Free Action may choose to drop prone when caught by suppressive fire using this action (see Suppressive Fire, p. 179). The defending character doesn’t need to make the Reaction + Edge test but is considered prone on their next Action Phase. If the suppressive fire continues, the defending character needs to use a Stand Up Simple Action to get back up, risking getting shot, or fight from the ground. If the suppressive fire has stopped the prone character still needs to use a Stand Up Simple Action to get back up.[/spoiler]
But actually, I'm inclined to just take the damage and roll edge:
Soak(Edge):
13d6t5 4 [13d6t5=3, 2, 1, 5, 1, 1, 2, 6, 3, 1, 4, 6, 6]
Damage negated without losing Ini.

Edit:
Ini 6
Ok, last action for Isaint for this round:
Free action: Multiple Attack
Complex Action: Medium Burst (6 Bullets) split at the two drones. I'll spend Edge on this one
(AGI 8 + Skill 8 + Smartlink 1 + Edge 5)/2 = 11
Shoot Drone 1 (Edge):
11d6t5 5 [11d6t5=3, 3, 5, 5, 5, 6, 1, 5, 2, 1, 2]
Edge Reroll:
1d6t5 012P AP 7 Dodge -2 + 5 Successes
Drone 2 (Edge):
11d6t5 3 [11d6t5=2, 2, 6, 3, 1, 3, 6, 3, 4, 6, 1]
Edge Reroll:
3d6t5 2 [3d6t5=5, 6, 4]
Edge Reroll:
1d6t5 1 [1d6t5=6]
Edge Reroll:
1d6t5 012P AP 7 Dodge -2 + 6 Successes
Edge 2/5
Round 3 Ini
Ini Round 3:
16+4d6 31 [4d6=3, 3, 3, 6]
The saints are clearly watching over Isaint