I had some problems with running this game under DOSBOX Staging, under the Heroic launcher. My goal here is to document and make the solutions to those problems easier to find online.

Problem of my own making: Files outside the Home directory
I've two SSDs in this computer, the larger of the two holds my games. The error I get is "Preventing an early 'exit' call from terminiating."

Solution: Open Flatseal entry for DOSBOX Staging, scroll down to Filesystem, flip the "All systems files" switch.
There's probably a more elegant, safer solution but this one worked for me.

Problems with Heroic: Nothing points where it should.

Solution: The official Heroic Wiki guide says to open in my case the file "goggame-1207658748.info" and take from there the DOSBOX launch command, then change that command to fit the particulars of my system. I did that. That was not the complete fix. Doing only this results in showing a launcher that immediately crashes DOSBOX. Or rather just exits.

There's a second file, "dosboxHOMM1_single.conf", which has to be altered. Lines 8-10 have to be changed to point to the HoMM directory, and the particular files within it.

I hope this helps anyone having the same problems I did.