Putty or butyl tape?

Wow, pretty strong statements here. I like working with the putty tape better. I picked up some butyl tape by mistake once and found it difficult to work with. Went back to the trailer supply store and got good information about the benefits and advantages of both types. For my application, on both my trailer and older tent trailer, the putty was actually better.
I do like the advice to "use what was there" before. I can't remember what the guy told me but it had to do with possible staining and black streaks on fiberglass siding. Again, talk to someone in the know.

I’ve had putty tape dry out too.

Definitely use the butyl tape. Putty tape is cheap and will not last. It will dry out, crack and cause a leak. It is no good for anything.

Use pure butyl tape not a putty butyl blend. It is the most expensive of the 3, but also the best choice. It is a bit more firm, but it will compress. Super sticky but that is what you want. Tighten the screws slowly and evenly, preferably when it is warmer as opposed to a cold day. The excess that oozes out can be easily trimmed and removed with a plastic putty knife. Don't use anything metal.

If it continues to squish out a bit over time, just trim it again. The butyl will remain soft and pliable for years to come, and will keep a good solid seal, unlike that cheap putty junk.

I used ProFlex RV sealant.
I put blue painters tape on the wall around the frame leaving about an 1/8" space before I removed the hatch frame. Applied a generous amount of ProFlex between the tape and opening and reinstalled the hatch. Once secured I cleaned the excess with acetone damp rags. Then I removed the tape and gave it one final damp rag wipe to remove the edge the tape left.

Using the painters tape helps cleaning the excess and leaves a real nice, clean appearance.

I would go by what I find, after removing the door. JMO, but of the two types tape, I'd use the putty tape. It compresses easily, and it is easy to trim the excess. If you want to purchase tape, before removal of door, get both, they're not expensive.

Jerry