My philosophy on this is, if/when my business grows to the point where I can't handle the bookkeeping anymore, I'll switch to something that I can hire out. And if that means paying someone to hand-jam in a year of transactions from my ledger files, so be it, but likely I'll write some translation software to make it happen.
Until that point, I'll keep doing my books myself with ledger :)
One small caveat as someone in the same boat. If you have to declare capital gains on transactions from multiple currencies, the "currency account" system that ledger uses is a bit strange for some accountants. I do my own book keeping, but I have an accountant who deals with the government ;-) He calculates capital gains in a way that I would say is arguably wrong. However, I trust that his way will be accepted by the government, which is all that matters ;-)
Until that point, I'll keep doing my books myself with ledger :)