[Zeliha] “would it take much longer to render it?”
Possibly, depends on your system and the length of the timeline. Maybe not. If you render everything, you may need lots of disk space depending on the length of your project also.
Try rendering only the dissolves and other effects first (using “render selection”). Then nest and appy the timecode filter…it may work in realtime.
Its entirely dependent on the capablility of your system.