Having never built a full product with any of the existing frameworks, take what I say with a grain if salt. 

I always struggled with expo and react Native. Never worked how I wanted it to ootb. 

http://capacitorjs.com seems quite promising. Mainly because you can use any web framwork, so porting something like cashu.me seems easier. 

Never really delved into it though, as a pure web dev, I always get frustrated when I go into the mobile world.  

 Porting cashu.me would be a dream. I tried with the tools quasar offers but couldn't get it to work really (although it compiled sometimes for Android and even iOS). Just the QR scanner alone was a big hustle for me and I failed.

Have you done anything like this before?