Shimano Adjustable Crank Arm Length

I currently run Shimano 105/Ultegra/Dura-Ace (2X11) components on my road bike.

• Chain Dura-Ace
• Cassette & Crank 105
• Derailleurs Ultegra

I am looking to replace my cranks when I wear out my next chain and want to experiment with different crank lengths (e.g 165, 170, 172.5, and inbetween etc.) without buying extra Shimano Cranks for $$$. I also want to make the jump up to 53/39 from 50/34 that is on there now.

I know Shimano does not make any adjustable length crank arms.

Do I have any off the shelf options to be able to use my other Shimano components and possibly use a 3rd party crank to get adjustable cranks without spending tons more than what I would on a Shimano Crank set?

Thanks

—- Update

I’ll probably go about trying to see if I can rent or try out a crank arm for a bit to ensure the fit is good and then buy the full ultegra crankset. Just as a bit of a follow up does anyone know if you can buy the right side crank arm on for an ultegra crank set new as I see the left side sold separately, but not the right?

Thanks