Freshly made MIDI fx AUv3 crashing on load on iOS

I’m sure this is just user error but I’m not spotting it

Made a project with VST3, AU and AUv3 and standalone , midi input and midi out and it’s a midi fx

Standalone Mac OS and plugin works
on iOS standalone works
BUT
Auv3 crashes in AUM with a rather odd error appearing in the logs - “[I-aa] 47: no formats specified”

any ideas? I’ve not really changed anything from the basic template BTW this is just setting up making sure I can build all the formats I want to achieve for this new product

For the record :-

made a new iOS/AUv3 only project - still had the same issue.

Ticked ‘is a synth’ option and then in the Xcode project changed the type manually to ‘aumi’ and it works.

Workflow question: do people tend to work with the exported projects or constantly round trip with the PROJUCER?