In the earliest days of the 3000's Transition Era, advocates for MPE/iX formed the OpenMPE user group. But the first campaign for these engineers (and a few businesspeople) was for the emulation of MPE itself. The ideal was that if MPE/iX source code could be turned over to the community -- since HP had no real interest in the future of the 3000 -- then the OS and its subsystems would be pushed onto newer hardware.
The ideal was open source for MPE/iX. That campaign assumed plenty of change was in the future of 3000-based software. The reality that formed about compatibility of software is illustrated in the everyday experience of Charon users.
One checked in this month with a summary of how smooth his software slipped into the Charon HPA environment. The emulation that paid off was virtualizing the RISC hardware. The caliber of the solution made things easy for Jeff Elmer.
I can say that since what is emulated is the PA-RISC hardware and not MPE, it seems unlikely that there would be any software incompatibilities. Everything we use (multiple third-party tools plus in-house COBOL/IMAGE software systems) just worked. It really was true that no one would have noticed a difference unless we told them.
The single item that we had to modify was in our backup job stream. We had a tape rewind command in the job that was no longer needed and which the emulator at that point (in 2013) did not understand. The "fix" took less than 60 seconds when I removed that clause from the job.
In summary, I would expect Speedware to work without incident but I couldn't speak to what combination would provide optimal performance (that is, which class HP 3000 should be emulated or what physical hardware should be under it). We spent a long time testing the emulator without charge before we proceeded with the purchase. I would think the possibility exists that Stromasys would extend a similar courtesy to you so that you could find out first hand with your data in your environment.
In fact, there's a Proof of Concept arrangement that Stromasys uses today to introduce its product for this kind of evaluation.