When I worked alone on slow-pitch or modified, at the plate meeting I would inform the coaches that certain "umpire" rules were in effect.
1) I always cover home first
2) I call what I see
3) I will eject anyone who charges me
4) I will discuss any call with the Head Coach only
5) The Head Coach is responsible for removing anyone ejected
6) the game is suspended until the ejected person is out of sight
Almost all of my solo games were on time limits.
It was surprising how both teams would "help" the ejected person leave!
I was getting so many ejections that I finally stopped doing solo games.