Modern Georgian is usually written as a unicase script called Mkhedruli. Capital forms called Mtavruli exist, but are not used to begin sentences or for proper nouns. Mtavruli are instead used for headings, emphases, etc. Mtavruli is used as ALLCAPS.

Unicode originally only encoded Mkhedruli, but with version 11 in 2018, Mtavruli were added as casing pairs with Mkhedruli.

Currently the Guess Case feature changes the first letter of a word is Mkhedruli. Since Mtavruli is only used in special circumstances, excluding the Georgian script from Guess Case would work.

See:
https://en.wikipedia.org/wiki/Georgian_scripts#Mkhedruli
https://en.wikipedia.org/wiki/Georgian_(Unicode_block)
https://medium.com/@akakirazmadze/mtavruli-letters-5665d0aec09c