First of all - never do #openbsd sysupgrade from unreliable connection like WebSSH on ipad (it will disconnect after switching to other app)!
Second - access to the console for vm on #openbsdamsterdam is great and easy - thanks @mischa for good intro to the setting after initial setup.
Third - sysupgrade process survived broken connection - #OpenBSD74 on the board - thanks #openbsd team!

Middlingly ancient #i386 #openbsd74 sysupgrade sailed smoothly! #releaseDay #openbsd

Primordial i7 amd64 #openbsd74 #openbsd #releaseDay seems fine, sitting through long pkg_add -u as said