Rear wheels are sort of mostly like this, ish. If you build wheels you'll get a greater understanding of what's going on but, on a non disc hub running gears then there is a fair amount of dish, the spoke on the drive side look almost vertical compared to the non drive side. Add a disc into the mix and the dish is a lot less, it's barely noticable, the spoke lenghts are maybe a couple of mm different at best. This will apply to 135mm and 142mm hubs. A 148mm spaced hub adds 3mm each side, so the dish on the wheel will be no different to 135/142mm hubs.
Take a look at the Hope hubs offsets and you'll get some idea of what's going on. Take a look at the RS4 road hubs as well. Pay attention to the different offsets between front and rear, your 110mm boost front probably has more dish than your 148mm rear. If you're really bored plug the numbers into a spoke calculator, the bigger the difference in spoke lengths between sides, the bigger the wheel dish. The last wheels I built were DT Swiss XM 421 rims on Hope Pro 4 hubs. The rear used 291mm spokes on the drive side, 292mm on the non drive side. As I said earlier, the offset on the 148mm is an extra 3mm each side.
Armed with new information you will now be able to make an informed decision on how much marketing bullshit the bloke in the bike shop fed you.
https://www.hopetech.com/_repository/1/ ... ANDPCD.pdf
