With all these vasectomy questions, you might be best off trying to interview a licensed urologist. You're correct that there appears to be very limited clinical research in humans regarding vasectomy in recent literature. From what I can find (emphasis mine):
Pamela J Schwingl, Harry A Guess,
Safety and effectiveness of vasectomy,
Fertility and Sterility,
Volume 73, Issue 5,
Peterson et al. suggest that there may be a trade-off between efficacy of an occlusion method and potential for reversibility. For example, open-ended vasectomies may be associated with a lower rate of congestive epididymitis and have a higher potential for reversal but may be associated with higher pregnancy rates. Removing a large portion of the vas may be associated with a low pregnancy rate, but re-anastomosis in this situation may be more difficult, with a low potential for reversibility. Cautery and coagulation methods tend to effectively seal off the ends of the vasa, but these require a more technically difficult vasoepididymostomy.
Open-ended vasectomy, or leaving the testicular end of the vas open, is performed to avoid the increased intraluminal pressure that leads to postvasectomy pain syndrome and to increase the chances of successful reversal. Some have shown that leaving the vas open eliminates potential for damage from increased pressure and is less likely than closed-ended vasectomy to be associated with congestive epididymitis, and in some cases, sperm granulomas. Others report that the method appears to result in increased rates of spontaneous recanalization. However, the method of occlusion of the closed-end and the use of fascial separation of the two ends seem to modify the rate of spontaneous recanalization.
Of course, all of the citations this paper refers to are pre-2000, so these don't address your point that "techniques for vasectomies and vasectomy reversal might have evolved since then." More recently:
Peter TK Chan, Marc Goldstein, Vasectomy and Vasectomy Reversal, Male Reproductive Dysfunction: Pathophysiology and Treatment, Chapter 34, Pages 385-406, 2007.
...men with postvasectomy congestive epididymitis may be relieved of their pain by open-ended vasectomy designed to purposefully produce a pressure-relieving sperm granuloma; however, it should be pointed out that some investigators have raised concern of potential vasectomy failure with the open-ended technique.
The associated reference doesn't compare the closed- and open-ended techniques, but one might infer a more facile reversal is suggested by increased failure rates (compared to cauterization methods). Beyond this, even the 2019 textbook Vasectomy Reversal contains no direct mention of the open-ended technique, so I think your best resource will be a practicing clinician.