If you try to add this plugin to Magic DosBox or any other DosBox you will hear the difference for sure.
Of course not everything games supports Gravis but if so you will be very satisfied for sure.
If you really want to using Windows98 you obviously need another DirectX than Windows95
but rest of files from the guide on Magic DosBox youtube channel is of course good for Win98. [link]
You only have to do: