I would avoid the V + R for digs if possible, since 1 room later you can trade R for 10 digs (and do it twice if needed).
If memory servers, this is what I do for trades:
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×First stage of loop: free -> ybr, yy -> r, ybr -> v, ybrv -> feather
-3y, -1b, -1r, 1 feather
Second stage of the loop: free -> yyy
-1b, -1r, 1 feather
Third stage of the loop: free -> 1r 10digs, 4y -> v
-4y, -1b, 1v, 10digs, 2feather
Fourth stage of the loop: free -> 2b, 3b -> v, 18digs -> feather
-4y, -2b, 2v, -8digs, 2feather
Fifth stage of the loop: free -> 1y, 1r -> 10digs
-3y, -2b, -1r, 2v, 2digs, 2feather
Sixth stage of the loop: free -> 4y, 4b, 1r, 1v, 5digs, 3v -> feather
1y, 2b, 3feathers, 2digs