I know the issue is about hearing yourself in a live situation, but can I borrow this thread to run some thoughts past you much more experienced players?
I'm fairly new to fretless (unlined, but the usual side dots) electric bass, but have some cello experience and know that intonation problems will get better with work. So I've been working very hard on the interval exercises in Steve Bailey's fretless bass book, all over the neck, not worrying about speed or even rhythm, but making sure I say the name of each note. Scales in the same way, naming each note out loud. Really concentrating and not letting myself get away with sour notes or intervals. Basically how my cello teacher taught me. Just starting too on the early pages of Ray Brown's DB method (adapting l.h. fingering to one fret per finger), and also trying consciously to read the notes on the page as I play them and say them out loud.
I'm making quite pleasing progress, and also finding that when I sight read eg Bach cello pieces that I'm familiar with, in the sense that I know what the next note will sound like but not quite sure yet where it'll be on the bass, my intonation is a lot better than when I'm playing pieces from memory or "improvising" (aka noodling or wasting time!) Also that playing with more treble in the tone than I'd really like shows up sour intonation better, esp on the lower strings.
How does this approach strike you? Any comments, hints, tips much appreciated. Sort of simple level though - Jake, I understand what you're saying, but I'm not at that level yet. Though I am finding the truth of the notion that eg an F# in a G major scale is different going up to what it is coming down.
Many thanks
Geoff