All OSPD words with one vowel followed by two different consonants are given below.
No four-letter heterograms in the OSPD are generated.
However, the I-at-the-end strategy cannot be used for OSPD heterograms; one eliminates ISM and ION but adds OBI, ANI and SRI in their place.
For example, among 11-letter words in OSPD I found 72 word pairs where the letter difference at each position was an odd number other than 13.
The OSPD has very few 12-letter words, and all non-crashing word pairs differed in at least one position by 13.
The largest shiftgroup for the OSPD
is 10, achieved for both two-letter and three-letter isograms.
Every word in Richard Sabey's square on the left is listed in the OSPD.
OSPD Official Scrabble Players Dictionary, Third Edition (1996)
First, ambidextrous word ramps are comparatively common, even restricting ourselves to words in the OSPD.
Thirdly, even given the relative paucity of longer words in the OSPD, left-offset 9-4 ramps restricted to the OSPD are exceedingly common.