Oftentimes there is no justice when it comes to tax law. With the major problems facing this country, congress considering the needs of RVers are not among them.
Although I have sited the Jackson case many times since it was published, the implication has not hit home.
To summarize, the Jackson's took their case to court and lost. Not because they didn't keep proper records, not because they didn't have documented receipts, not because of missing mileage logs, not because of a lack of client records. Basically it boiled down to Code Section 280 A(d) which defines a dwelling unit.
For your convenience the underlined line above contains a link to the entire ruling.
So, what are we left with? Basically, treat your business as though you don't have an RV and take the time tested deductions that have stood through the years. Be through with all your documentation and the required record keeping.
Most importantly, enjoy your RV and your lifestyle. We are indeed the lucky ones!