[KevinH]

In epub3 with recent Sigil versions you should be able to use BookBrowser to delete the toc.ncx file but on an epub 3 that file's function has been replaced with a specially structured xhtml file usually called nav.xhtml (but sometimes toc.xhtml) that has been identified by semantics as the file to be machine read by the reader.

If I were you, I would use Sigil's Epub3 tools to delete the ncx, then create a pure xhtml toc (not meant to be machine readable but human readable) using the Create HTML Table of Contents menu.

Edit that table of contents to create your list for the human reader.

But that still leaves the limit of 99 for Kindles. The only way to fix that is to organize the nav to have less than 100 entries. You can do that be creating some useful structure in your document for the poems and making those structure entries h1, and reducing the others to lower headings.

Isn't there some natural structure you can use for the poem collection? Could you organize them by poet, or time, or into subject matter groupings, or style groupings, or even metre groupings? Then create new HTML chapters for each of those groupings, give them h1 headings, and replace individual poem headings to some lower heading or use a paragraph and style based heading. Each of those new chapter groupings could start with links to all of the poems that fit that category (ie provide a short table of contents).

The recreate the toc, and use the TOC Editor to hide any lower heading entries.

The user then sees your html toc and can access any poem by a short click while the nav is then used to navigate to the major grouping chapters which should be far fewer than the 99 limit.

There are example saved searches in Sigil to mass demote or promote headings to make this easier.

My 2 cents...

BTW if you are uncomfortable with epub3, there is a Sigil plugin that will allow you to create a epub2 from it (from Doitsu I think).