There are a lot of us here like that - just because we have the knowledge to be the best Server janitor we can be doesn't mean we want to put up with the faff that's sometimes involved. I mean, I could do everything I do with FreeNAS now with FreeBSD if I wanted to, but I don't want to, because I don't want to deal with it either (nor do I relish being the only person in my house who could possibly understand even simple tasks like restarting a jail). I mean, that is what FreeNAS is about.
Doesn't mean you shouldn't tune for your situation though. A lot of it is set it and forget it anyway. Learning the various options regarding NFS mounts is time well spent. For example,
I know NFS will never run as fast as the jails accessing the zfs pool.
isn't exactly true. Nor is it really that hard to do once you do some research in to it.
You can do a quick and easy test right now, in the GUI - turn off sync for your NFS share(s). It won't hurt or mess anything up to try it. See what your transfer performance is like then. If it is much better (and it probably will be unless you have a different problem) then you know one problem to solve. You can either keep it that way (not a great idea, generally, though there are use cases for doing so) or put your log on a separate, faster device, preferably one with high write endurance. You don't need a lot of space - even 10GB is overkill for a 1Gbe connection. A small Optane would do the trick. Read the recommended SLOG device thread on these forums.
These days I also recommend NFS4 w/NFS 3 security model - also select-able in the FreeNAS gui. NFS4 is more performant than NFS3 and a lot of the little tweaks for the latter aren't as necessary with the former. And for most home server users the extra layer of security in NFS4 is more trouble than it's worth - which is why the option exists to use the older security model in FreeNAS, and is even exposed in the GUI.
In the end though, if you are bothering to run FreeNAS at all, and the application you want can be run in a jail (or as a plugin jail), then I'd recommend that. A lot less hassle - which is what you are trying to avoid - and not any more difficult to manage day to day. Docker has its uses for sure but when it comes to FreeNAS I only use it for lightweight apps that simply aren't available for FreeNAS/BSD. Which are fewer than you might think.