Since there were *no* examples of writing a hardware driver using an LKM on OpenBSD, and there are plenty of examples of new ones being added to the static kernel, I don't think this in any way makes adding hardware drivers more difficult. To my knowledge over the last 16 years or so, the only real uses for LKMs have been kqemu (discontinued upstream) and dellflash (perhaps it works on laptops but it never worked on any poweredge which I tried it on). Note that neither of these are hardware drivers.
Some of the less-helpful "community" members could do with a kick up the arse though, better to not post than to post an RTFM without at least pointing out which bit of TFM to R. I'm sure that often they don't know the answer themselves. (Not to be mistaken with mails from time-starved people that are equally short but do actually point people in the right direction...)