The text message you get from MoT specifically says that "you have 90 days of usage per year" thus you can potentially come for a 15-day trip up to 6 times a year and you'd still be fine.MrClass wroteI was in the same situation; got an iPhone XS plus. Traveled to Beirut; got the message upon inserting a new sim; 6 months later, traveled again, phone still works despite being well over the 90 days period.
Only God knows what the heck is going on
I recently got a Xiaomi Mi 9 SE. I don't think it's officially available here so I will let the 90 period run and see what happens. Hoping that it will not be included in the customs list.