Add passthrough without compromising ventilation

I'm looking to purchase a laser cutter, but I'm new to laser cutting, so I would like to hear your recommendations. I will be primarily cutting SRPP, which is essentially polypropylene, as well as some sort of plywood or balsa wood for prototyping. The manufacturer of the SRPP recommends an (at least) 100W CO2 laser. Ideally it would cost at most \~5k, but there is a lot of wiggle room in my budget. I have a few more questions. The SRPP comes from the supplier in 24" x 48" sheets. Ideally I wouldn't need to cut it beforehand, as that could present issues with delamination if done incorrectly and generally would be a nuisance, so I would prefer that the SRPP could fit in the laser cutter without any resizing. I see that some machines have "passthrough" that allows you to put in materials larger than the machine's working area. Does passthrough compromise ventilation or is it not an issue? If it does, would you recommend just getting a machine with a working area that is at least 24" x 48"? Also: Lightburn. I see some machines have an option to include/be compatible with Lightburn for about an extra $200. Is it worth it? What are the alternatives? Like I said, I'm a rookie in this space, so any help would be appreciated. Thanks!