Personally, I think just the once is sufficient.
Going for an obscure names is an interesting decision to make as an author, and I'm fascinated by how readers interpret these names too.
Obscure names in fiction
I remember being uncertain about the name "Hermione" whilst reading the Harry Potter series written by JK Rowling - and whilst I clearly remember having a debate about how her name should be pronounced with a fellow Potter-head, I can't actually remember a passage in the book where her name was spelled out phonetically.
In fact, I don't think that debate was settled until the first Harry Potter movie came out!
How your audience will interpret obscure names
I can't speak for everyone, but when I'm reading - I tend to skim over words to try and read as quickly as possible. This is especially the case when I'm caught up in an exciting plot, and can't wait to get to the conclusion of a scene.
When names I don't recognise come up, I often come to a conclusion on how they should be pronounced at a glance - and it's only when I reflect on the matter later on that I give some proper thought as to how a character's name was intended be pronounced.
From an author's perspective, I think the decision on how often you instruct your readers on the pronunciation of a character's name will depend on how pivotal an understanding of the name is to your plot or character development.
Seeing as you're considering multiple iterations of the name, I'm guessing it's important to you that readers pronounce your character's name properly - but I'd recommend you ask yourself what value this really adds to your character, and whether it's worth breaking your narrative to include phonetic instructions?
Personally, I don't think it's worth losing the flow of your writing just to repeat a name's pronunciation more than once. If I wrote a passage like the following:
"She poked her head out of the door and called out 'Ameqran', the q in his name emanating from deep within her throat, as is typical in this part of North Africa"
I'd expect that the reader would be committed enough to remember this pronunciation without any further prompting.
Ambiguity can be a good thing too!
I think it's worth mentioning that ambiguity in the way a character's name is pronounced can be used as a literary device in itself.
The best example of this that I can come up with is in DBC Pierre's novel, Vernon God Little.
The first chapter features a teenage boy called Jesus, who I initially read in the same way as the name of the lead character in another popular book you might know.
It wasn't until a few pages into the novel that the author decided to have someone call out the character's name - pronouncing it hey-zoos - and thus transforming the character into a confused teenager of Mexican heritage.
Finally, I think its very tempting these days to opt for obscure names because a lot of the entertainment we enjoy in modern times is through film and television.
Whilst Game of Thrones can get away with having characters called Aerys Targaryen (pronounced "AIR-eez Tar-GAIR-ee-in"), I think it's crucial to remember that filling your novel with names that require a pronunciation guide can create hard work for your readers.
If you find yourself in this situation, then maybe you should consider writing a play instead. That way you can have as many Tybalts and Mercutios as you like!
