Ada target and Unicode support

[Richard-52]

I have been working on a personal project to make an Anltr4 target for the Ada programming language which I am happy to open source if I ever finish it. To understand how the runtime works I am using a lexer and parser generated from the example Ada grammar. The syntax in the grammar allows Latin characters but not the broader Unicode character set which raises some questions about Antlr4 Unicode support.

I have searched and found some information about Unicode support but no information regarding my specific questions. At the moment I don't want to explore the Antlr4 tool itself so I'm hoping someone already knows the answers:

1. The Ada language standard permits all Unicode letter_uppercase, letter_lowercase, letter_titlecase, letter_modifier, letter_other and number_letter characters in identifiers and that is over 135,000 different characters. Am I correct in thinking IntervalSets are used to manage them and therefore Antlr4 can handle this number of characters and without excessive memory use or significant performance penalty?
2. Ada is also a case insensitive language and if I recall correctly there are roughly 3,000 Unicode characters which have lower and upper case. Will the internal Antlr4 method of dealing with case insensitivity support this number of characters without excessive memory or performance penalty?