We should make it possible to transfer Maps between client ans server, but I don't know how soon we'll get to it.
I'm surprised it takes a long time to add 150 entries in a map. How long does it take? It's possible that the actual time taken is the time it takes to process the map (and search for elements to translate on the screen). You can test that by separating the creation of the map from setting the <Labels>.
If the problem is in processing the map, the solution will require an optimization of that process.
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