In my spelling reform proposal for Spanish, I floated the idea of allowing for equally acceptable spelling variants in some cases, to allow for greater ease for those who have variant pronunciations of some words. I believe this shouldn’t cause many problems when reading for those who don’t have those pronunciations and don’t go for those spelling options, provided the options don’t affect too many words or cause collisions with other words. If the reader is also familiar with the variant pronunciation, there will be even less chance of a reading problem.
I believe a certain amount of this is also necessary in a reformed spelling for English. The fact is that for many English words, there is more than one acceptable pronunciation. And sometimes, these variant pronunciations don’t have to do with systematic accent differences between different varieties of English, but are equally acceptable even among people who have what appears to be the same exact accent.
Two examples: data, where the quality of the first vowel can be TRAP or FACE (I say it with FACE), and amphitheater, where some people (like me) pronounce an F sound for the PH, and others a P sound.
Similar cases are herb and vehicle, the first of which has a silent H in American English but a pronounced one in British English; and the second of which does not have a silent H in some accents of American English.
In cases like these, I think the best solution is to allow variant reformed spellings: datta/data, amfitheeater/ampitheeater, urb/hurb, veeikl/vehikl.