The way I do "leaders and enders" is I really don't have a "leader". The leader that is in my sewing machine at the start of the project is actually my "ender" from the last project. So every time I finish a sewing session the last thing I do is stitch a scrap "ender". I then cut off my actual project and leave the ender in my machine until the next sewing session. But on the occasions I don't do an "ender", (like when I just attached a binding) I will start my "leader" by physically holding both my top and bobbin thread while taking the first stitch of my scrap leader. This avoids any thread bird nests, which is what I use leaders and enders for. So I can chain stitch without hanging on to those threads each time I start a new unit. My machine typically does not "eat" the first bit of fabric. Even when starting with a triangle. But if your machine typically does that you have few choices. You can get a single hole needle plate, you can religiously, without fail always use an "ender" which then becomes your "leader on the next sewing session, or you can use a spider.
One more option, assume you forgot to use the ender. Start your leader scrap at the midway point to avoid the fabric munch. Then when you need the ender, snip off your half sewn leader and complete it as an ender.