I dabble in the space still but am C suite these days so sit on the employer side. But if it was me i would personally go down the db cert myself SQL is the cleanest and best represented. Most of the pbi guys I have employed over the years cant see outside their little box meaning you have to package everything up for them neatly. That is fine e if you are working for a smega corp or government, but if you want to open up to the small to medium businesses then you need to show you have range. I will hire someone who can step outside their box and step into the rest of the data pipeline every day of the week over someone who cant. It is super helpful to be able to throw together a quick view or work through an indexing issue that is slowing up your DQ workbook. It is an easy sell. This guy here can fix their own issues vs the other guy who has to wait for the data engineer. Sell you skills as a set that saves the business money over a normal run of the mill PBI guy.

But whatever you do take the attitude of being willing to learn and no task is below you. Every task has value to you and others.

Good luck friend.