Horse racing betting: is early cashout ever worth it?

I’ve been doing more horse racing multis lately, and I keep getting tempted by those early cashout offers. Had one last weekend where I was 4 legs into a 5-leg multi, and the bookie offered me a £600 cashout on a potential £1.5k win. The last leg was a 6/1 shot, so I took the safe money. Of course, my horse ended up winning.

When do you take the cashout? Is it ever the smarter move long-term, or am I just getting scared too easily? Curious to hear if anyone has a system for this!