Printing past bed mesh - bad Z offset

[quick furnace]

For the most part my z offset is perfect, except for the very outermost limits of the print volume, that weren't actually probed and arent a part of the bed mesh. I think what is happening is the firmware is matching the curve of the closest probed point.

Basically at the limits of my print area the z offset is just a tad too high. See on my heightmap how the center is raised and the edges curve down - It's like this curve down continues past the mesh in the firmware's logic, and it is over compensating causing the Z offset to be too high only at the print volume limits.

Is there a way to change this behavior or tune it?

[burnt zodiac]

please post your printer.cfg and klippy.log

normally, your heightmap will only show the probed area, not the whole bed

[quick furnace]

It's only showing the probed area in the picture. That's my question exactly - what does the printer do for parts that print past the probed area? Everything that prints in the probed area is fine. Using X as an example: Mesh covers X=20 to X=150. Everything within that prints fine. But if I have a part that spans the entire X axis of the bed from say X=2 to X=175: everything from X=2 to X=20 and X=150 and X=175 has too high of an offset. I'm talking too high as in variation in the bed, not like the printhead starts printing in air or anything. Less squish than if it were within the probed area basically.

[bed_mesh]
speed: 400
horizontal_move_z: 12.5
mesh_min: 20,25
mesh_max: 150, 155
probe_count: 5,5
fade_start: 0.5
fade_end: 2
split_delta_z: .025
move_check_distance: 5.0
mesh_pps: 2,2
algorithm: bicubic
bicubic_tension: 0.1
zero_reference_position: 90,90 # This is the new Relative Reference Index - Set to Bed Midpoint```