A high percentage of panels are glued with urea formaldehyde resin and because it is a thermosetting, non-reversible adhesive it has no practical limitation on heat resistance. In other words, urea formaldehyde resin glue lines will not soften at any temperature. A small proportion of your panels are glued with polyvinyl acetate adhesives (PVA) and this glue line will begin to soften at around 160F with danger of bond failure at 200F plus or minus 10 degrees. This is normal for all PVA whether cross linking or not, and there really is no way this can be significantly increased. However, it should be understood that glueline softening is also a function of time and glue line depth as well as temperature. In a finishing operation the time under a high temperature of perhaps 300F, probably will not be long enough to significantly soften a PVA glue line, especially given that your panels will have 3/4 inch of glue line and the depth of heat penetration will be quite small even with exposure of a minute or two.