With a very new word, we shouldn't necessarily be hamstrung by what the dictionaries say, as they can be slow to catch up with new usages. But in this case some of the major dictionaries did respond quickly to the linguistic effects of the pandemic.
The OED added several new entries in May 2020, including self-isolation, social distancing, PPE, elbow bump, etc. But at that stage they seemed to recognize only Covid-19 as the name of the disease. It was in July that the OED listed Covid as another name for the disease.
The online Oxford lists Covid-19, with Covid as a variant. Merriam-Webster online lists COVID-19, with several variants noted, including covid with no caps. Wiktionary has entries for COVID, Covid and covid, with COVID as the main entry.
So there is some dictionary support for the no-caps spelling. When I look at actual usage patterns, I see marked differences between the US and the UK. In recent records from the News on the Web corpus, the UK has COVID 289 times, Covid 736 times and covid 46 times. From the US we have COVID 827 times, Covid 246 times and covid 39 times.
So it seems the all-caps form is favoured in the US, while Covid is preferred in Britain. But in both regions the no-caps covid is occasionally seen.
I feel this is enough to justify accepting covid as a Chi word, but I'm in two minds whether it should be common or rare. Some people will probably refrain from playing it, being convinced that the word must be written with at least one capital letter. But on the other hand, anyone who does play it might be surprised to see it classed as rare. Any thoughts?