H&Y has just started a kickstarter campaing for what looks like an interesting variable step-up ring system. The goal is to save space, money and time switching filters. You can read about it on DPreview:
https://www.dpreview.com/news/2656352784/h-y-revoring-variable-step-up-rings-allow-filters-to-fit-multiple-lens-thread-sizes
and the kickstarter campaing can be found at:
https://www.kickstarter.com/projects/revoring/revoring-a-variable-step-ring-for-your-camera-lens-filters?ref=Fundedtoday&utm_medium=referral&utm_source=dpreview-e.fnd.to
The video on the kickstarter campaing convinced me to support the campaign.
Enjoy