For the variable font I want only the weight axes to be visible, which is easy to do but I want a specific interpolation value of the width axes to be used through that variable weight axes. So not the Condensed master, not the Expanded master but a “Regular” width family with a visible weight axes.
Add the thin and bold width interpolations as instances
Add instance as master for those two
Delete all the other masters
Delete the width axis
Take care of the remaining font info settings. Make sure that there is no font conflict if both the two-axis and the new single-axis fonts get installed simultaneously.