IMHO unless you have relatively flat ground 3 is just not enough and a 7spd derailleur offers a much wider range at a much lower price point.
To add to this. I had an Electra Moto 3i with a Sachs IGH. Shifted nice, worked perfect for that matter but the bike needed more gearing. Low wasn't low enough and high wast high enough. Even on a standard ctuiser its nice to have more range. ALSO while taking the rear wheel off isn't something you do everyday you do have to undo the shift cable and if its a coaster the brake arm, vs just the axle nuts or a quick release.
My .02
Last edited by JehD; 06-28-21 at 11:23 AM.