Hmm, good idea. There are names that have the exact same pronunciation yet have different patterns of declension, for example:

- Ástvaldur -> ur,,i,ar - Baldur -> ur,ur,ri,urs

The "aldur" ending is pronounced in the exact same manner, but applying the declension pattern of "Ástvaldur" to "Baldur" would yield:

- Baldur - Bald - Baldi - Baldar

The three last forms feel very wrong (I asked my partner to verify and she cringed).

Spoken Icelandic is surprisingly close to its written form. I wouldn't expect very different results for the trie if a "phonetic" version of names and their endings were used instead of their written forms