Traveling right after applying for UK visa (Global Talent Visa)

I am in the following situation. I am an EU citizen living currently in my home EU-country. I will start a new job in fall in the UK and the employer will endorse me for a "Global Talent" visa. However, I can only apply for the visa 3 months in advance, say July 1st. At that time I actually need to travel to non-EU country B for my current work, where I would stay for more than two months. I don't need a visa for country B and can stay there for up to 6 months. My future employer told me now that I should not travel between applying for the UK visa and receiving a decision. Getting a decision can take several weeks and would greatly interfere with traveling to country B. The solution my future employer now suggests is going to country B and then apply online for the Global Talent visa using the UK ID app.

Does anyone have an experience similar to this situation? Or does anyone have any source that would confirm that this is possible? I did not find anything definite about this. Actually, I did not find anything that suggests that I should not travel while waiting for the decision (which is only a problem if you are applying from within the UK). Of course in my visa application I would explain my travel to country B etc.