Congrats,......
WE Masks are a great bird.....and offer great challenges

...........Mine also wont take Green Milk Seed..........One pair have just fledged a clutch and it was interesting to note their feeding habits....almost like clockwork
In the days prior/during egg laying they both took a small number of termites each day then backed off to almost none
At 7-12 days they progressively took significant quantities of termites
At 15-20 days they took termites but showed an marked exuberance for green feed, especially Rape leaves......
By the time the young fledged they had reduced their termite intake.........
They have gone down for a a second round but threw one nestling at about 7-10 days old.........I'm not sure whether they still have young.....they're pretty quiet .........I only hear them around 12 days old or thereabouts.....
and the parents have backed off on the termites but take a fair bit of green feed.
Mine nest mostly 40cm - 1m from the ground whilst their roost nests seem to be as high as 1500mm....
I'm interested in hearing others experiences with these fantastic.....and rare....finches