Capping this ring

dear @Joshua_MacGregor
to get a better response please post the file -

there is
_planarSrf (curves must be planar within document tolerance)

some of your surfaces need to be trimmed and joined…
boolean operations might work (…not so well)

kind regards -tom

mimsftr.3dm (1.1 MB)

dear @Joshua_MacGregor

find attached a version that might help - is this what you re after ?
there have been a few issues - i solved them in a very “fast&dirty” manner.

the upper edge was not planar and the surfaces did not meet at (1)
I used
to fix this.

the lower point (2) was super wavy and not closed - I think you re expecting to much from a networkSrf.
I trimmed away that part and replaced it with some helping-Surface:
_line, _trim

now this is a bit a bricolage data but should do its job for a lost wax 3d-print.
Don t use it to apply for a jewellery-Cad-Job ;-D

hope this helps - kind regards -tom

mimsftr_tp_dirty.3dm (5.3 MB)

if you want to stay with the _networkSrf Approach
maybe one way to improve would be to use tangential-helping surfaces (green)
and only build the upper part as _networkSrf

… trying to help - but i am not a big fan of _networkSrf…

I deleted my posts because the best solution to your problem is the make sure you have planar curves before running your network surface.

not sure if you guys would see this but thank you so much for everything. I appreciate it alot