The IPA's own 1948 Principles document explicitly instructed that diacritic marks 'should be avoided, being trying for the eyes and troublesome to write'

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The specific feature blamed for Lepsius's Standard Alphabet's failure to spread — its dense stack of diacritics — is the same feature the successor organization's own founding design rules explicitly told its members to avoid. Jo Verhoeven and A. Hirson, in a chapter on phonetic notation systems, reproduce verbatim one of the original design principles from the Principles of the International Phonetic Association (1948):

"Diacritic marks should be avoided, being trying for the eyes and troublesome to write."

This is the International Phonetic Association stating, as institutional design doctrine, that heavy diacritic use is a fault to be engineered around — on readability ("trying for the eyes") and ease-of-writing ("troublesome to write") grounds. It is not a later historian's critique but the organization's own rule, from the body that produced the notation that displaced the diacritic-heavy universal alphabets of the previous century. It corroborates, from the winning side of the standards contest, the shape of the claim that completeness-via-diacritics loses to usability — the pattern the vault tracks through claim-ipa-descends-from-lepsius-via-ellis-palaeotype-and-sweet-romic, claim-war-of-the-dots-competing-braille-systems-1829-1932, and claim-bana-2012-ueb-adoption-kept-nemeth-code-parallel.

Two caveats scope it. The quote reaches the vault secondhand — read through Verhoeven & Hirson's chapter, not from the 1948 Principles document itself — so it is cited as a Tier 2 secondary quoting a Tier 1 primary, not a direct read of the primary. And the 1948 principle names ease of writing and reading, not typesetting cost specifically; it is adjacent to, not identical with, the print-shop-economics mechanism documented in claim-printing-office-type-shortages-constrained-victorian-phonetic-notation.