Mate, the US allows customization of F-35 as per customer requirements and there might be differences due to this factor. Israel, Finland, and Japan requested such customization. Israel also have in-house F-35 maintenance and Finland wants to do the same.
There have been other contracts related to specific modifications of the F-35 for FMS customers, even just this year. However, while thin on details, these have differed from the latest announcement in elements of their wording. While the costs involved are broadly similar in each case, they have applied to modifications that apply to multiple unidentified FMS customers, rather than just one. Among these earlier contracts, one valued at $13.7 million is for “support of sustainment efforts for flight test instrumentation air systems,” which could again point to the Israeli-specific test jet. Beyond the possible need for a refueling probe on its A models, Finland has already said that its aircraft will feature some significant differences compared to other F-35As. According to the Finnish Air Force, “the solution encompasses the maintenance capabilities to be built in Finland as well as spare components and replaceable assemblies for exceptional circumstances that are under the sole national control of Finland as well as participation in the multinational maintenance network.”
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These customizations are country-specific. Like Finland cannot have Israeli customization and Israel cannot have Finnish customization. This is how it is.
The US is not open to selling F-35 to UAE in the present. UAE has Chinese 5G infrastructure so this is a barrier that is to be addressed in some way or form.
Interestingly, the US developed and sold most advanced versions of F-16 to UAE - these were even better than American versions. But the US put a cap on numbers.