Adding commands to G-code

Hello,

First of all thanks for the great plugin!

I'm trying to print with silicon, which though successful so far, is messy between layers. The extrusion rate is controlled by a 2/3 valve using the fan on/off (similar to the Frostruder Mk2 method). Basically I need to add M106 (pressure on) at the beginning of each layer and a M107 (pressure off) at the end. To add manually it's very time consuming!

Is there a way to do this through the Config settings? The 'layer_gcode' allows the addition of one command before each layer, but the tricky bit is adding a command at the end of each layer.

Otherwise I was thinking of inserting the commands into the list as a secondary process. I've tried with the 'replace' function though this isn't the right way to go about it. The text below features the end of a layer, followed by a retraction movement, then the start of the next layer. The two commands in red are what I wish to add:

G1 F1200 X86.25 Y1.95 Z0 E376.01

G92 E0

M107

G1 F600 E-3

G1 F4800 X86.25 Y1.95 Z3

G92 E0

G1 F4800 X80.44 Y31.16 Z3

G1 F4800 X80.44 Y31.16 Z0

M106

G1 F600 E0

G92 E0 G1 F1200 X38.56 Y36.73 Z0 E42.25

If anyone has any advice, or could point me in the right direction that'd be awesome.