For 22 of the following 23 instances (available in MiniZinc format and Essence format), the computed lower bound (lb) on $\lambda$ has been shown to be feasible.

$v$	$b$	$r$	lb($\lambda$)
9	300	100	25
10	325	100	24
10	350	100	22
10	360	120	32
15	350	100	24
19	20	9	4
9	70	35	16
10	100	30	7
11	150	50	14
12	200	75	25
13	250	80	22
6	50	25	10
6	60	30	12
8	28	14	6
9	36	12	3
10	30	9	2
11	22	10	4
12	44	11	2
13	26	6	1
15	21	7	2$^*$
16	16	6	2
19	19	9	4
10	37	14	5

$^*$ For the instance $\langle 15,21,7 \rangle$, the best known solution has $\lambda = 3$ and it is unkown whether there exists a solution that matches the computed lower bound of 2 (note that not much effort has been put into answering this question).