Q: How is ilo.blocks built?

With a few exceptions (which I'll cover a little later), the
blocks have been written entirely within Konilo.

Konilo is intended to be used as complete system. It doesn't
have any easy ties to facilities the host may provide, so it
can be challenging to get data in or out. Arland and I are
working on external tools & code (in C, Python, and RetroForth)
to provide better options in the future.
 
So, for me, the blocks are written using either the basic editor
in the ilo.rom or the Tuhi editor (loaded from the blocks during
the default startup).

This isn't a problem for me. I've used variations of the basic
editor for decades, and the Tuhi editor is mostly a thin shell
over this. The editing process is lacking in some aspects. It's
not easy to alter a small part of a line. Cut/copy/paste only
handle a single line at a time. But it is functional, and I've
written thousands of blocks using it.

My editors are unlikely to appeal to most people. But that's ok.
Konilo is primarily written for my use, and there's nothing
preventing users from writing their own editors. In keeping with
the spirit of "Code It Yourself" [1], I encourage this.

The exceptions here include the glossary, which started with
an external list of words that were passed through a program
in RetroForth to create the initial form. This turned a line
like:

  s:for-each	word	rom

Into a template like:

  0 Glossary: s:for-each                                             
  1 
  2 Data Stack:    -
  3 Address Stack: -
  ...

A line at the start set the first block number, and a bye was
inserted at the end to shut down Konilo.

The template was then injected using a Unix shell:

  cat template.txt | ./ilo

Edits to add stack comments and fill in descriptions and example
data was then done using the block editors in Konilo.

A similar process was used to insert the dictionary data for the
english (dict/voa) and toki pona (dict/tokipona) entries.

[1] https://pestilenz.org/~ckeen/blog/posts/ciy-manifesto.html