I have finally dialed in the value. Apparently 0.11 is too much.
I printed the "toleromancer" a 0.1mm offset test print with 1mm, 1.5mm, 2mm, 2.5mm interlocking features:
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This allowed me to fine tune the values with "real world" application: fitment.
0.000 didn't fit, as expected.
0.100 fit but snugly, so not optimal
0.110 fit, but with snugness on the smallest 1mm part, kind of counterintuitive
0.105 fit perfectly with 0.1mm tolerance throughout including the 1mm part.
Hereby I present you the Toleromancer: