I’ve been through Synfig core and Studio for UK/en_GB. I made a handful of changes - mainly meters to metres, centimeters -> centimetres, millimeters -> millimetres, and a couple of other minor tweaks. If someone wants to give me access, I can go an mark these as 100% verified.
I also noted that we have some typos in the (US) source code.
For core -
Neighbours (UK spelling) should be Neighbors (US spelling)
“Value that define whether the step is centerd on the value [0,1]” should be “Value that define whether the step is centered on the value [0,1]”
“Unrecognised canvas variable” should be “Unrecognized canvas variable”
“When cheked the area outside the Radius are not distorted” should be “When checked the area outside the Radius is not distorted”
For Studio -
“A Activepoint already exists at this point in time” should be “An Activepoint already exists at this point in time”
Also, should “translator-credits” be translated into the relavent language? Or substituted with the actual name of the translator?