Hi! Also new to the group.
The mechanic is correct in saying the clutch may not handle it well, the engine will be perfectly fine, but, you may find the clutch slip or just fail outright which i have seen happen with one of my friends. if you really want to tune it, id consider an uprated clutch if you want to spend the money on one, or maybe not a full stage 1 map? like an eco type? but id either recommend not tuning it and keeping your clutch alive or tune it and deal with the clutch later. or 3rd, maybe get a car that can fully handle a tune better (not meaning to be rude)