Sorry, what I am trying to say is that there won't be much usable lip, in terms of lay on the table protection, once a thicker glass screen protector is applied. (I'm not talking about a glass screen protector covering any part of the X4 case--just a case-friendly one which fits within the exposed screen area when the X4 case is on.) This is because the Atmos X4 case has a very small amount of lip itself (its built-in screen protector, because it has a raised plastic rim around it, gives the case more lip, but when it is removed, the amount of lip that the actual case has is quite small. Tempered glass screen protectors tend to be on the thicker side, so once one of those is in place, the top of the screen protector will almost be level with the lip, leaving you with very little 'lay on the table design' protection.
In terms of needing to clean the adhesive side of the screen protector, I can see your point with this type of screen protector, particularly if you use the X4 in rough conditions. And I suspect the suggestion above with the Dawn detergent and the canned air (and maybe with the addition of a rinse in distilled water, to reduce water spots, should probably work well. Personally, I have never needed to do it, for two reasons:
1. My iPhone leads a very quiet, protected life. It encounters very little in the way of dirt and challenging conditions.
2. I never keep cases and screen protectors on for very long, because I always have something new in the pipeline to review.
Good luck! Hope this helps!