How to delete hundreds of user presets in Lightroom Mobile (iPad/iPhone)

Dear Lightroom experts,

I've started again to explore Lightroom mobile on my iPad again.
Currently I do have the issue, that I do have hundreds of presets in Lightroom Mobile (on both iPad and iPhone). (Unfortunally I tried to import a ton of VSCO presets some time ago).

Can you help me out with a way to delete those presets?

- The only way I found to delete is one by one one the mobile device (way to long process to delete >1600 presets 

- I've tried to delete the presets on Lightroom on my Mac. Unfortunately they do not show up there

Any recommendations?

Thanks a lot,
Daniel