A port of Daggerfall Unity to New 3DS family systems.

It theoretically should be possible as Unity did support the New 3DS line of systems.

It also has native controller support so not much remapping would need to be done, as for touch screen features there's a few obvious things that could be done.

Realtime Map with markers for your current objectives or being able to place custom ones down with notes about the location.

inventory management.

A journal like UI showing the progress on whatever quest you're doing and what should be done next, also with a notes tab so the player can keep track of anything they want.

As for 3DS exclusive features? I believe we can look to TES:V on Nintendo Switch for some inspiration.

A spell that allows the player to scan any amiibo to spawn a chest with a summoning circle, containing randomized loot. But if the player scans in certain amiibo, the chests would contain certain items or spells. Scanning in the Loot Goblin Amiibo could have a large sum of gold and jewels in the chest. Using the Solaire Amiibo could grant the player Holy Word.

Obligatory gyroscope camera controls.

Maaaybe having Miis saved to the player's system could show up as random NPCs in towns/cities? I of course don't mean as Miis, but using Daggerfall's existing NPC models and replacing their names with the ones matching the Miis.