On my phone I use the Japanese keyboard and just switch to the Japanese flick romaji when I need them (which is a lot). A lot of how awkward it is goes away or gets easier with use and practice. You start memorizing where each romaji character is and what you need to do to get to them. I also like that you don’t need both hands to use the flicking keyboard. And maybe due to how weird it is to use with two hands, it is slower than using the normal keyboard. My biggest gripe is with any words (Japanese or English) that have double letters or characters. For example the word “middle” or 「正す」are very annoying to type on the flick keyboard because you have to wait for the thing to let you use the same character again. It’s only really a problem for words that have doubles if either あ、か、さ、た、な、は、ま、や、ら、わ、and @,a,d,g,j,m,p,t,w. As those characters are the ones you have to wait on. Any other characters can be typed quickly and easily with the Japanese flick keyboard on the phone.
In closing, it’s tricky to learn, but the more you use it and the more practice you have, the easier it becomes.