At work we discuss this a lot with Mike himself. The problem is that current day fonts didn't exist back in 87, so a lot of little details exist on the sets due to the manual process they did back then, and that's simply impossible to be replicated via fonts.
They used a variety of fonts, essentially what was available in the shops at the time. It wasn't until late TNG when a lot more things were first done digitally. Lots of early LCARS were indeed Compacta Light, while others were Helvetica Ultra Compressed (of which Swiss 911 is a clone, so MA is half-right). But yeah unless you go in there and adjust kerning and do some resizing to make up for the fact that we're essentially using digital reproductions, there's no perfect font for these.
This is really fascinating. May I ask: Do you have a "close as can be" font you typically use for LCARS and tags? Or is your process more involved to make things match on a case by case basis?