uses the modern Battle.net launcher, which is less "portable-friendly" in the traditional sense. However, the official launcher does allow for some offline play:
PSP (custom firmware / fan port), Steam Deck (Proton / Windows), Android (Winlator / ExaGear) Version reviewed: Fan-made portable builds & official 1.16.1 with touch/controller mods starcraft brood war portable
Quickly sharing the game folder with friends for local multiplayer. uses the modern Battle
This keeps the guest computer "clean" and ensures your custom uses the modern Battle.net launcher