The method of gluing longer 'carrier' boards on to your short material is a valid solution for short boards. This is an exaggeration but, you get the idea.
plane small stock.JPG
The carrier boards are milled true in height and then glued to the passenger material. They should be as tall as the tallest portion of the passenger board to allow the feed rollers to control the work. Once the passenger material is milled true, the carrier boards are ripped off at the tablesaw.
The boards you are talking about are long enough to be jointed and planed on my machines. It seems your snipe problem is what is driving this discussion. The amount of snipe you describe is a good reason for tuning up your machine. I prefer none and align my planer for that. If you have one of the lunchbox planers that is renowned for unavoidable snipe, another member once posted something like this as his solution as opposed to creating a burn pile made out of lots of wasted cutoff ends.
Snipe cure long stock.JPG
Instead you end up with a burn pile made out of lots of wasted carrier material. A tedious solution to be sure but, we either spend time or money in the shop. One way or the other, ya gotta pay .