I’ve used both Bionic Reading while on Reeder, and the Open Dyslexic font while on Kindle, for several years to similar effect.
My personal finding is that it makes the work my eyes need to do to keep on the line, and move from line to line easier.
But I will note that the largest increase in reading speed for me, up to 800 words per minute, came from single word focusing. There are tools, such as speed reader mode in Emacs, or an old browser extension called Squid, that take the readable text and put it all on one line, then move the text through a window that stays fixed on the screen.
By training yourself to relax and not read the words aloud, I was able to increase my reading speed from around 200 wpm to over 800 wpm. The trick is to slowly ramp up the speed, and not just jump up to the fastest speed possible. It’s also important to remember to blink.
Alternatively, text to speech works for to in a similar way, and I’ve found that I can handle 2.5x - 3.5x speeds after a few hours of training. As a bonus, nobody else can decider what you’re listening to, and you get some funny looks.
Let me know if others have found similar techniques to work for them.