Does anyone know the ratio of registered teams in a region to the worlds spot for teams in that region?
There isn’t a ratio, per se, but Appendix B of this document should answer your question.
https://www.roboticseducation.org/documents/2019/08/qualifying-criteria-vrc-2019-2020.pdf/
For Taiwan, there are 3 high school spots and 1 middle school spot for the world championship.
Currently yes. But I think there are more teams participating in Taiwan than previous years, and I am figuring out if the number of spots will change on January.
I think there are only 7-8 middle school teams competing in Taiwan, so its not really possible for them to add another spot for middle school.
A more applicable way for you guys to get into worlds might be through skills. According to the VRC qualifying criteria, the remaining of the world spots is given through skills. Since you guys have a pretty good robot already, you guys can hardcore practice on driving and autonomous, then join a small regional (or even host your own) competition to increase your skill points.
I think aiming for top 15 in middle school skills (abt 60 points) can get you a spot in worlds. For reference that is two 7 stacks and 3 towers, definitely achievable through practicing. Just make sure your robot is fast enough that it can stack and score in towers under 3 seconds
Just to be clear, this is only the case within each state or region, not world-wide. The skills scores are used only if there are allocated spots unawarded at a regional or state championship (due to double-qualification or teams qualifying at multiple events, such as signature events). If that is the case, then the skills rankings is used to qualify teams for Worlds.