David Charlesworth
It should be clear that Stanley and Record aimed for chipbreakers which terminated at 45 degrees.

This angle is important. Exceeding it results in a shaving trap, if the mouth and C/B are set very fine.

The new style chipbreakers from L-N etc do apply pressure to the back of the blade, which is also slightly bent in the process. They are much more massive and do not have issues with their relationship with the lever cap.

L-N (and other) chipbreakers are ground at 25 degrees, usually with a slightly blunt square edge. They need a little attention from a stone, not grinder. Sharp 43 degrees is good, this can then have the microbevel of ones choice added. Say 50 or 75 degrees if you are pursuing the ultra close settings which work so well.

best wishes,
David Charlesworth