Tube mods look simple yet issues are amazingly common:
Crunchy, sticky and wobbly switches.
Wobbly body threads.
Loose ill fitting 510 threads.
Random quality.
Insufficient vent holes.
Some don't flush fit RBA.
Excessive voltage drop; I don't care except when cloud chasing.
I've heard some magnetic switches are nice so your magneto may be a decent mod? Perhaps wobbly body threads which is a minor infraction.
I almost love Nemesis in spite of issues. Switch needed TLC to function decent. Locking ring is thin; not issue if careful. 510 threads are loose and shallow but haven't caused me a problem; have cause problem for 2 others I know of.
Bagua near perfect except can't flush fit some RBAs on my version.
I would consider a real thing if certain issues are ironed out. Some clones are so close but no cigar. Close enough for a good vape though.