Sometimes, it's nice to have a custom funnel.

This one prints in 0.3mm layer height in PLA. It's parametrizable, but with a 0.4 nozzle, 0.9 wall thickness gives two layers.

I originally designed this to print in vase mode, but had print failures in case mode, but this traditional funnel works fine.

Use a brim so there's some surface in the first layer for the print to stick to the bed.