Is there a way to change the game's data while it is playing?

I’m trying to make a sort of Twitch stream where comments make enemy units spawn, hindering the player. While I’m able to change the enemy unit’s parameters using Event Assembler, the changes only come into effect when I reload the ROM. Does anyone know a way around this?
I’m using FEBuilder with an FE8U ROM; please tell me if you need any more information.

It is theoretically possible, but practically impossible.

I think that it can be realized by preparing all types of reinforcement in advance and switching by flag or something.
Since the number of flags is fixed, even if they are rewritten from the outside, they will hardly cause any problems.

Since the UnitRAM structure is scanned each time, it is almost impossible to change the number without stopping the program.
I tried to make a cheat function that would kill all enemies, but it failed.
Although it is possible to rewrite HP etc., it is quite difficult to increase the number of lists.

This would not be possible without the same technique as live patching.
Live patching is a technique used to update a very expensive system that cannot be stopped even for a second.
We don’t have a very expensive program like a telephone switch or currency trading, so I don’t think we have to work so far.

Did you by any chance see my own twitch streams where I had the twitch chat screw with my game and spawn enemies?

I did it via a lua script. VBA-Rerecording is able to load lua scripts. I had the script read and interpret my twitch chat, then make modifications to the game’s RAM according to what command the chat used.

It’s not a public script, but that should give you an idea of where to start.