Mine is a Gen 1 m90q for reference. I was almost not going to buy it because I already had the DrayTek card and my heart dropped when it measured at 155mm. But I thought "to hell with it, I'll just massage it in". Luckily I didn't have toI did measure some 18 months ago on an earlier Tiny, so it's possible they've rearranged the front antenna assembly to give a little more room. We've had people with issues with cards smaller than yours and some who had to take off (and replace afterwards) the front fascia to fit cards in, so I did try to be a little conservative (but not 16mm conservative!).
But I'll take your advice and re-measure, if we can expand the range of cards that will fit that's a good thing.
Maybe we need another column in the model table for "max PCI-E length" for those cautious like me?