Indeed you would. If the shop does load it for you, you must also specify all the options inside the sketch - which c.t. inputs are allocated to which phase, etc. There is a list and a description of each in the file emonTx 3-phase PLL User Doc.pdf, which comes as part of the download of the sketch, from Github GitHub - openenergymonitor/emontx-3phase: emonTx 'approximate' 3-phase firmware or Update to 3-Phase PLL sketch - #15 by Robert.Wall
(Done any other way, it would be unrealistic to have one download for each possible permutation.)