There are two issues here:
First, you have to pay more for faster. I have a Dillon D-Terminator electronic scale. Fast, reliable, accurate, settles on a value very fast (faster than a beam scale), is sensitive to .1gr trickles.
The only problem with it is cost, at $139.
Faster costs. Whether it's a good powder measure or a scale, you pretty much get what you pay for.
The second issue is Unique. It's not a good powder for metering compared to, say, WST or W231. It's just the nature of Unique. I never had particularly good results metering it out of any measure. But I've had WST remain just dead-on a 4.7gr charge over hundreds of rounds on a LnL press.
I understand the reloading on a budget. Been there. But budget means you're giving up some things, primarily speed and ease of use (fortunately, quality is *not* one of the things you give up).
Perhaps you use up your Unique--or if you have only a little left, hold it in reserve for SHTF purposes--and then try a better metering powder. There are many which will work well. I haven't tried them all, because once I found that WST and W231 work great for me, I stopped looking.