I have some intermediate layers in glyphs that have linked metrics. In these layers the linked metrics shown as out-of-sync in the intermediate layers, because the metrics are interpolated.
This means I manually have to go into each layer, right-click the intermediate layer one-by-one, and choose Re-interpolate metrics. If I Update metrics for all layers the intermediate layers with be set with incorrect non-interpolated metrics.
This issue results in having a Glyphs file with several blue triangles with exclamation marks, and I can’t know for sure if the metrics are correct or not.
What I’d like to happen is that the linked metrics for intermediate layers are interpolated when I select a glyph and execute Update metrics for all layers.
“Re-interpolate Metrics” re-interpolates the metrics. It calculates the metrics based off the closest (intermediate) masters. This might result in different values than the ones obtained through a metrics key.
“Update Metrics” doesn’t (shouldn’t) interpolate metrics. It does the same as clicking on the red arrows for out-of-sync metrics. What is maybe confusing you is that “for all Masters” doesn’t apply to intermediate layers (as these aren’t masters). You need to do those manually, or via a script:
for layer in Layer.parent.layers: