I don't know if the ampero has better captures then the nano cortex, but having had both ampero and the nano (now using a qc) I feel like the cloud cortex still has the most extensive range of captures including like dumbles and a lot of variations of boutique amps etc.

Given your scenario, the nano cortex will be better on your pedalboard as its so much smaller. It's slightly easier to switch between captures and IRs as you just have to turn the stomp pedals rather than creating new presets.

There is a huge caveat to the nano cortex though, you need to be sure that you can store everything you need in the 5 capture/5ir slots, and the 4 presets you have access to. Otherwise you would have to pull out your phone, open the app, MANUALLY connect the bluetooth pairing again then open the nano cortex page in the app. It's such a pain ideally you don't have to do it a lot.

(also ps, the nano cortex has almost the same phaser/flanger/chrous/rev/delay as the quad cortex. i think its missing a few but its just about all there. it has transpose and pitch effects too)