The short answer is that it is a matter of taste.
The longer answer is that "small caps" were developed for use within running text so that "all capitals," when you stand back and squint, have a similar texture and color to the regular surrounding text. This was typically a hand-crafted font and not just a smaller point size.
From that perspective, "small caps" is not intended to be mixed with "regular caps." And if you subscribe to such things, then this is the only correct thing to do. Then again, it used to be a thing to wear stockings and powdered wigs.
However, it is obviously a common thing to mix small caps with regular caps for stylistic reasons, so why not?
Personally I have used them in the past and even done things like "Technological backgrounD," but my current taste is all caps or nothing. I think that if you are thinking about it and you think it looks "not so great," then trust your judgement and go with all caps. Use a Display Titles font if available and maybe increase the tracking (letter spacing) slightly.
If there is a departmental style guide which prescribes typesetting, you should follow it.