SciresM already confirmed 4.1.0 and below getting a softboot method.
....a softboot method that will require user interaction as in, opening up a browser and visiting a web (or self-hosted) site. Not as friendly/easy as just using the T-X dongle, especially if you're out and about somewhere.
Emunand on the Switch will be worse than it was on the 3DS because you'll need to perform the step above. I think the ONLY advantage that Atmosphere's emunand will have over the SX Pro is Atmosphere will probably support (via forked builds) eShop games sooner. SX Pro will support backups sooner so pick your poison.
However, T-X said that emunand is something they're looking into so I can see a time down the road where you boot your console with the T-X jig/dongle, boot into emunand of the latest firmware and play your eShop games that way. Or who knows maybe T-X will figure out a way to let us play eShop titles, then, IMHO, emunand will be pointless....... like it eventually was on the 3DS. But after looking at the eShop games, and realizing that I've already played all the ones I want on other platforms, I have zero interest in anything from that library. Thankfully, their 1st party games all have a physical release and I've been collecting those. Have my 256GB microsd card ready to go!
Remember though, as others have said, if your emunand gets banned...... so does sysnand.
After I install the SX Pro, I'm keeping my 4.1 Switch off-line. When I start coming across games that require 5.1, I'll gladly update. I have no interest in emunand or a softboot method that requires me accessing some internal/external site. Heck, I might just update to 5.1 now.