hi @padejumo,
I'm glad you found the issue.
That's really hard because it likely depends on the context and your own preferences. One important point is that if you annotated with a spans recipe, make sure you didn't make an overlapping spans as its permissible with spans recipes but not ner. If you try to train ner, you'll get an error if there are overlapping spans.
Not sure if you've seen it, but there's also a spaCy template project that compares spancat vs. ner:
You could also try modifying your suggester function. Also, are you using data-to-spacy so as to run spacy train instead of prodigy train? I doubt that'll do much for memory, but it does give you the ability to span characteristics via spacy debug data (see the ner_spancat_compare project for more details).
It may be a not an option, but any way you could even reframe your problem by splitting it up someway and using textcat instead? This post mentions it and a few related ideas.
Hope this helps!