If someone could check and advise?

LB 27.5 & 29″ rims on Superstar Switch Ultra hubs (ie Novatec)

Measured the ERD using a pair of 300mm (inside of J to end of thread) at multiple points and get the following:

27.5: 554.5 & 554.5mm
29: 592.5 & 592.2mm

Using DT swiss spoke calc
3 cross pattern
2.0-1.8 DT Comps
12mm brass nipples

I get the following recommended lengths, actual in brackets:

27.5:
FL 269 (268.5)
FR 271 (270.9)
RL 269 (268.7)
RR 268 (267.8)

29:
FL 287 (287.4)
FR 290 (289.6)
RL 287 (287.4)
RR 287 (286.6)

Looking at Rose they have the following:

268, 270, 272
286, 288, 290

Do I round up or down when I have an odd number?

Slightly worried on my ERDs,

measured using 300mm spokes wound into the nipple so they are level with the base of the slot. The spokes then overlap and using the ID measurement on set of calipers against the J end to tension them and subtracting this from the 2x spoke length. This should be no difference to using shorter spokes and tensioning them together (but not crossing) with the OD measurement.

Rounding to the nearest (ignoring the recommended) I get my order to be:

27.5:
FL 268
FR 270
RL 268
RR 268

(48x 268, 16x 270)

29:
FL 288
FR 290
RL 288
RR 286

(16x 286, 32x 288, 16x 290)

+ a couple of spares.