looks like someone already ported ctrBootManager
Yeah, the topic is here...
https://gbatemp.net/threads/release-ctrbootmanager9.417159/
Anyways, emuNAND for me because the arguments for sysNAND either don't apply or don't balance the arguments for emuNAND.
An argument for sysNAND that doesn't apply for example is "you can remove your emuNAND from your SD and save space". Not entirely true if you want to run apps that need 9.x or stuff like that. For a very specific example, if you need GW for cheats, you won't reasonably boot that from your 9.x emuNAND to your 9.x emuNAND... Not that I use them but I don't see why I would kick myself out of possibilities.
And the arguments that don't balance are:
-emuNAND is tons safer (you can't mess up an update, it will always be patched (unlike sysNAND which is only unpatched if you fail your installation, but it can be) and it's easier to reflash when you don't have a hardmod...)
-sysNAND saves some kilobytes by not installing VC twice. Most of space saving was already possible with forwarders but even without forwarders, you are not wasting space with VC...
Now one may say "if safety is your priority, then use menuhax, not a9lh". Well, I didn't say it was the number one priority. Menuhax+emuNAND is indeed the safest way of using a 3DS but a9lh+whatever is just more convenient. And among the two most convenients options, well see above, emuNAND wins in my opinion.