In general the main issue with mounting is print and the substrate do not expand and contract at the same rate over time with temperature changes which results in buckling of the print, and general failure of many mounting adhesives. This leaves two choices, either t-hinge the print so it can freely expand and contract, or permanently mount it. If you use something like 3M super 77 and you hand mount it, you are sort of mostly permanently mounting it but not as permanent as dry mounting. The advantage of the dry mount is two fold. One, the adhesive is fully applied (with spray you might miss an area), and the press fully activates the adhesive across 100% of the surface (assuming done properly of course). Now small items you can do by hand, and you might have a permanent enough mount, but larger items get tough. So it comes down to how big is the print and how long do you want it to last.