For those of you who jumped on this hoping to get an easy TB3 25g adapter, you may want to take a closer look at the model numbers. I ended up with a TLN
S-3102-D00, which I can't really find references to on their website. But as soon as you plug it in on Windows or Linux, there's a pretty obvious difference:
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AFAICT this version is actually a ConnectX-3 Pro instead of the ConnectX-4 Lx, and as a result has no known firmware updates. I did try in case I was crazy and this cross flash might actually work (and the model number discrepancy didn't matter) but things still don't look promising there either, with either the 3102 or 3252 image:
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If anyone has successfully flashed when their device presented as CX3-Pro, please let me know, but there might be older variants roaming around on ebay that aren't gonna do anything better than 10g SFP+ (maybe 40g QSFP+ if I'm lucky).