EW Scrip Collectable Tier Changes

Scrip collectables got changed in EW and now they can all be turned in, meaning that the game explicitly informs us of the minimum size of these fish.
The tier 3 value is not the maximum, so that currently is still not possible to determine with 100% certainty but the maximum is more likely to be found due to abilities forcing large fish and the collectables being fish farmed explicitly at large sizes.

Now it would appear that the tier 3 minimum is the top ~10% of the size bracket for the fish.

Taking Lunar Deathworm who very likely has been found at its maximum size already due to its popularity:
Max: 295.1
T3 min size: 277.4
Min: 118.1
10%

Echinos, which is a purple scrip fish as well:
Max: 82.5
T3 min size: 77.6
Min: 33.0
~9.9%

This applies, approximately, to all scrip fish examined with what is documented as their largest found maximum sizes.