I thought it was pretty much accepted that TFA's RY4 Double doesn't even have any tobacco flavouring in it, and it's just vanilla, caramel and EM or somesuch. I much prefer to use Holy Holy Grail as a base for taste (it's delicious on its own), but if I'm honest I don't detect any tobacco in that either. ATF's @fear Holy Grail inspired recipe "Cardinal" is well worth a try as he adds a couple of tobacco flavours, but I found it wasn't a good steeper and at its best for the first few weeks only. What worked for me was 9% Holy Grail and 3% (SC) Cohiba, steeped for a month+ and thereafter just keeps getting better as it ages. A lovely creamy bright tobacco RY4, more akin to a tobacco custard really at 3+ months.
The closest DIY recipe or oneshot I've tried to date (and I've tried many) to mimic smoking tobacco is probably ATF's @fear "Abuela" recipe. It is outstanding as a mango and vanilla infused premium cigar. Well worth a try if you are into DIY.
RY4 Double or Holy Holy Grail are great bases to build on and you just need to find and add your favourite tobacco flavours to them to create your ideal "RY4". I have just worked my way through most of the Flavorah range and I didn't find a "keeper" among them although there are some decent ones there. I am starting on Inawera next and I believe they use actual tobacco extract in many of their flavours, so I'm looking forward to starting on them, especially as I already very much enjoy their Am4a pipe blend standalone at 3% to 4%.