Is a COA required to appeal a district court's denial of a motion for stay of the habeas proceedings

QUESTIONS PRESENTED FOR REVIEW 1. Is a COA required to appeal a district court’s denial of a motion for stay of the habeas proceedings made under Rhines v. Weber, 544 U.S. 269 (2005), for exhaustion purposes? 2. Whether the Eighth Circuit's pro forma, non-reasoned, and blanket denial of a COA in a capital case insufficient under 28 U.S.C. § 2253(c); Slack v. McDaniel, 529 U.S. 473 (2000); Miller-El v. Cockrell, 587 U.S. 322 (2003); and the heightened due process standard for capital cases? i