I have the same tablet. Jt have not been very successful for my goals with it. I wanted to download largevarea say the western USA and spent a lot of time downloading I large chunks to a 128 gig sd card. I downloaded at zoo level 15 and my chunks were like 350,000 tiles. All looke. Ok but when using bcn it would allow only a detail level of about 9 to 11 I found out later that at least for Gaia there is alimit of 100,000 tiles . Why you ask would I do that well plans change . For example I bought my jlur in Idahowas going to drive through silver city and through some bad lands to northern Nevada but a big storm came in and I diverted through eastern Oregon.For the price of that GPS puck you can buy an Android table with the functionality built in. I use a Lenovo 7" tab A2 (there are newer ones out now) and for $100 it will get you everything you need including an SD card slot for adding maps. I use Back Country Navigator and Here (both off line) without issues.
The other thing is I lost my usb charger for it and the new one while working won’t stay hooked up.
So my question to you is how much. Have you downloaded at a time and did you have any. Zoom issues.?