Ran code through easy coding standard (ECS):
https://github.com/easy-coding-standard/easy-coding-standard

which upgraded the b2evolution arrays to PHP 8 standards, etc.

Manually fixed the arrays in b2evo installation file(s) to correspond to PHP 8 -- as ECS failed to do it.

I tried Rector https://github.com/rectorphp/rector automatic upgrade to PHP 8 but it left b2evolution 7.2.5 in an unstable state... always.
Tried to call the attention of the Rector developer by opening an issue but the developer was not interested.

Accordingly,

Implemented dirty hacks to rid of fatal errors the front display of blogs, including the Dashboard Contents and Comments tabs (yuck!)

https://github.com/Metztli/b2evolution

Limited testing... Notwithstanding, to not display the warnings -- which had beginning to plague b2evolution 7.2.5 since PHP 7.4 -- you should make sure to modify your
conf/_advanced.php file and change the value, at line no. 49, from:
$display_errors_on_production = true;

to
$display_errors_on_production = false;

Work in progress but feedback is useful. NO WARRANTIES whatsoever!