Northern Khmer on iPhone

[Richard Wordingham]

Does iPhone support the use of Northern Khmer in Thai script?  I would
count an interface in Thai as support.

The reason I ask is that I tried entering the word กฺี <U+0E01 THAI
CHARACTER KO KAI, U+0E3A THAI CHARACTER PHINTHU, U+0E35 THAI CHARACTER
SARA II> 'he' and got a dotted circle.  I also got a dotted circle for
the alternative spelling <U+0E01, U+0E35, U+0E3A>.

This might be an application issue.  The application I was using was
Line.

Richard.