Genius 231

[MissSpell]

I usually take my time with Genius - I got a whole month before the next one! And I am making some progress with 231 - but I need HELP! please.
I cannot work out the theme - other than, possibly, 'measurements'?
and
I don't follow the method of transferring bits from clue to clue.
eg 20A ??n?a??s Adds ornamentation to fancy seals, securing coloured liquid

[JJ109]

All the words to swap are measurements!

The input for 20 across is Linkases
"LINK" is the measurement andit replaces "INCH"
Coloured liquid = ink, inside an anagram ofseals is the parsing for Linkases. The definition though is Inchases (ornamentation)

[JJ109]

https://www.merriam-webster.com/dictionary/inchase
https://www.merriam-webster.com/dictionary/enchase

[JJ109]

Please note the words to replace each other can be different lengths
eg 1a) A 5 letter measurement is replaced by a 4 letter one. All other letters remain in the same order

[MissSpell]

THANK-YOU so much!