I eventually managed to sort this quandary out by sluring ,position 1 , c to g quarter note quaver harmonic slurs alternating each quaver between just vertacle engagement with just lateral engagement until I could actually do that rather well and it didn’t take long.
Something else related to this is that I practice daily begining and ending harmonic slurs with a long tone on BOTH the bottom and top note and ending on the top note with as clear and centered a note as the bottom note.
Which is to say that if the top note is getting squeezed doing faster higher quavers , long tones at the top at the end of quavers helps keep me on track dodging the dreaded clamp .