I never got the hang of Excel, it was easier for me to use a legal pad, calculator and a pencil at work and I didn't need spreadsheets any way :-)Instead of doing math to scale each measurement I use Excel, I like to use spreadsheet to set up the formula. You have to decide on proportions/percents, but you enter how much meat you ended up with after grinding and it tells you the needed weight of herbs & spices. And metric is so much easier to calculate than teaspoons.
For lemon flavor, are you using the juice or zest?
I'm a fan of the lemon zest powder from Penzey's (if you're in the US). It is a lot easier to measure and more consistent than zesting a lemon. And keeps in the fridge for way longer than a dried up lemon.
Although the recipe I used had both metric and US measurements, when it got down to the small amounts they used teaspoons in both, probably
because their scale choked on those tiny fractions of grams like mine does.
I used fresh lemons for the zest because I prefer fresh ingredients when possible, but its a pain grating lemon zest and next time I'll probably use something out of a bottle.
I think it might mix better any way. I'll look for that Penzeys....