Private rules for LT (in LibreOffice extension): possible?

Can I somehow add and use my own grammar rules for the LibreOffice extension that will survive extension updates? I. e., keep them in a separate file that could be copied or symlinked so that LT sees it.

Here is my story.

In 2000-2014, there existed the Eurasian Economic Community (EurAsEC / ЕврАзЭС in Russian). It has been replaced by the Eurasian Economic Union (EAEC / ЕАЭС in Russian). Still, some people use the outdated ЕврАзЭС when they actually want to say ЕАЭС (I use the Russian abbreviations because I am not sure if the problem exists in the English-language domain). Well, I created a rule as follows (I will need another one for unabbreviated names, but I don’t know how to handle multiple declensions, well, it’s another story):

<category id="Svoi_pravila" name="Свои правила">
    <rulegroup id="Nazv_org" name="Названия организаций и структурных подразделений">
			   <message>Организация больше не существует. Возможно, имелся в виду <suggestion>ЕАЭС</suggestion>?</message>
			   <short>Имелся в виду ЕАЭС?</short>
			   <example correction="ЕАЭС">Встреча глав государств <marker>ЕврАзЭС</marker> состоится в декабре 2022 г.</example>
			   <example>Встреча глав государств ЕАЭС состоится в декабре 2022 г.</example>

The rule works, but the only way I know is to paste it to grammar.xml, which means that it will not survive an update and I will need to do it again. Hence, the question above.

P. S. Яков, может добавите правило к русскому набору? Или это кажется слишком специфичным?
P. P. S. After some search, I found the following thread:
No luck then?

Not yet, but I’ve added that now for the next release (LT 6.0). The approach uses a file named grammar_custom.xml, as documented here.

Great. Waiting for the release. Thanks!

For the record: I tested the suggested approach in the freshly released 6.0/LO It works. Thanks!