As far as I know, it is not eligible to have 2 simultaneous visa applications. However, looks like stage-1 is not a visa application.
Does somebody have experience applying to stage-1 during the process of skilled worker visa consideration?
I think there is no issue with applying for a global talent visa, as long as you are eligible for it.
From your question, I guess you are currently in UK, and the only restriction is clearly stated that …
Who cannot apply to switch to this visa
You cannot apply to switch to this visa if you’re currently in the UK in one of the following circumstances:
- on a visit visa
- on a short-term student visa
- on a Parent of a Child Student visa
- on a seasonal worker visa
- on a domestic worker in a private household visa
- on immigration bail
- you were given permission to stay outside the immigration rules, for example on compassionate grounds
You must leave the UK and apply for a Global Talent visa from abroad if you’re in one of these categories.
Read more at: Apply for the Global Talent visa : Switch to this visa - GOV.UK