If you write with your right hand and use an ink that needs to dry, it is a bit better to write left-to-right, to avoid smearing the ink. If you are typing on an older computer or typewriter, it is better to write left-to-write because it is (was) really difficult to write right-to-left, given that the machines were primarily set up for left-to-right scripts. These days, nobody uses squid ink or IBM PCs. Consistent direction is superior to alternating direction (you have to know whether you're on an odd line vs. an even line to know whether the current line is RTL or LTR), so boustrophedon poses an additional complication. Since in Arabic-script based languages numbers are written LTR, that could be a tiny disadvantage (switching direction), but still people cope, and it's only the programmers that would have to write code for systems that are not consistently LTR who suffer. But those problems have been solved.
I do not see any practical way to write Persian script LTR, so a change in direction would mean a change in alphabet, almost certainly Latin. You should consider the case of Tajik which used to be written in the Persian alphabet, then over the last century there were experiments with Latin and Cyrillic, and purportedly there is a plan to re-introduce Persian. Script changes tend to make old literature inaccessible, which in the case of Persian would be a disadvantage (not fatal, look at Turkish). Even so, older literature tends to get reprinted in contemporary alphabets, so that 150 year old Norwegian books get reprinted in contemporary Latin. I conclude that the LTR / RTL choice is a linguistic red herring.