Max, I agree. I-110 and CA 110 are two different roads, so I would count each as separate (similar to I-210 / CA 210). Now, as for 1's point about different states; I suppose I could say I clinched I-210 (CA) and I-210 (LA) to note I clinched both segments.
In 2018 while in Oregon I clinched I-405 in the Portland area. Who knew that infamous number existed elsewhere besides So Cal?
Now, how about other discontinuous routes, like CA 1? I've been on all segments between San Francisco and the Capistrano Beach area (including the Seacliff section), but not the northern segments above San Francisco. I guess that makes it 'driven on' but nowhere near a clinch.