Thanks for sharing your ideas.

I do a similar technique as the original poster, however, I named my security "mBTC" because bitcoin denominations have so many decimal places. I just multiply all my trade quantities by 1000 and divide the price by the same. This works well because Quicken is setup to handle lots of decimal places in a security's price, but not so many in its shares.

For example, buying 5 bitcoin for $250.45 would go in as:
5,000 mBTC @ $0.25045

The other difference in what I do is that I mark network transfer fees using ShrsOut transactions in the investment account. This workaround isn't ideal because they show up as cost basis related transactions when you generate a capital gains report, but it's the best I could come up with. I'm curious to hear if anyone else has a better solution here.