lowryder alternatives?

are there any alternatives to lowryder for a fast outdoor harves

yes there is,Runderalis is early flowering

Ruderalis Skunk is the most powerful descendent of Cannabis Ruderalis. By bringing the auto-flowering advantage to Skunk #1’s dependable potency and yield, we have created a tough, rewarding outdoor hybrid for growers with short and unpredictable summers. C. Ruderalis grows wild across north-eastern Europe and is able to survive the harsh and varied climate through adaptations such as its auto-flowering capability. Wild Ruderalis plants flower according to age rather than a declining photoperiod, which allows them to take advantage of the warmest, brightest part of their brief growing season.

(Sensi)

can't you just start flowing light cycle right off the bat?

I'm growing Early Misty, it's all indica, so it's stoney, but it stays pretty low and flowers pretty early. It's also supposedly one of the strongest outdoor strains that Nirvana offers - but never tried it personally.