A quirk in the Inyo NF is only putting some FR sign posts up. Sometimes a side road will be labeled without the main road being identified. Such as 3S07, a main road, won't be posted, but 3S07H, a short side road, would be.
The MVUM will have most of the labels, and by using dead reckoning from a the prior labeled intersection, you can figure out where you are. I'll take snapshots of the FR signposts that I come across. Breadcrumbs.
In lieu of Avenza, I download the NF's particular MVUM pdf to my laptop, then screenshot a specific area of interest for a given adventure, then download the screenshot to my phone for an offline map.
Currently, I do not have a strong enough cell signal (2 bars) to download Avenza, it went from three minutes, then to 15 minutes, when I canceled the install.