My equipment is pretty similar to yours, in fact mine is way more similar to something you can find in a farm rather than a all in one system and I brew anything on it, from raw ales to amazing NEIPAs. You can get you efficiency anyway, although beware that any change will have an impact, I brew anything in mine as I said, so one day I'm step mashing for max fermentability, the next one a traditional sahti mash and then a double decoction mash, I'll experience changes on efficiency on each method, but I can account for them because I've brewed a lot using each method so I know what to expect. Milling can have a big impact too, any adjustment that you fo for whatever reason will have an impact.
As I said, you need to work out your efficiency on a normal brewday first and do it every time you overshoot your OG or undershoot, that way you'll know whats going on, because you have a reference, let's say you have a 75%, if one day you get 80% then you know that whatever you did different boosted your efficiency by three points. Otherwise you're pretty blind when it comes to your mash, it's like brewing without a thermometer or means to measure your gravity, you can do it but there will be so much out of your control that it will just make things harder