here is the scoop on the Skyliner from RVA to HS (caveat on Monday 26 Oct 2020 so other days will vary) ...
should you walk to the Caribbean Beach station?
- if you get up early and don't mind waiting in line at the RVA station take the Skyliner from the RVA station; otherwise, probably worthwhile walking to the Caribbean Beach transfer station
- first seven parties in line in the morning at RVA have priority, the go straight to the HS line (ahead of anyone else at the Caribbean Beach transfer station)
- I walked up at just after 8am and there were already four parties in line
- eighth+ parties wait in line behind anyone already at the Caribbean Beach transfer station (mostly Caribbean Beach guests but possibly some Pop Century folks that may beat you there on their Skyliner)
- ~10-15 minute walk from RVA station to Caribbean Beach transfer station depending on your pace
time to get to Hollywood Studios
- 8:30am RVA station starts boarding to Caribbean Beach station (9am official opening, 10am Hollywood Studios opening)
- 8:35am I stayed outside until I saw everyone boarding, then joined the line once most folks had boarded
- 8:37am boarded at RVA station
- 8:40am line empty behind me at RVA station (so now just walk-up folks)
- the good news ends here ...
- 8:43am entered long line at Caribbean Beach transfer station
- 8:50am all cars coming from RVA are empty (so very few people still coming in, occasionally the odd car will come with folks but few and far between)
- 9:21am board from Caribbean Beach transfer station to Hollywood Studios
- 9:28am exit Hollywood Studios station
- I didn't do temperature scan, security, or park entry but it seemed doable in the ~30 minutes left until you needed to be in for 10am Rise of the Resistance passes but it would be tight
- trip from Hollywood Studios to RVA was ~15 minutes
- if you're going early in the morning back to RVA (not sure why you would unless you were doing this testing) you can talk to a cast member and they'll let you on the Caribbean Beach transfer station to RVA section ahead of the Epcot portion opening; you actually end up going in the accessible section to bypass the people waiting to go to Epcot from the Caribbean Beach transfer station; this is pretty useless information to most people but I found it interesting

if you're dedicated rope droppers you probably don't mind waking up early enough to be one of the priority parties from RVA so you'll probably be fine; if you're semi-dedicated rope droppers, you might consider walking to the Caribbean Beach transfer station to join the line you're going to join anyway
personally, I think we're going to drive to Hollywood Studios when we go; I like being in control of my own destiny (I don't like leaving things to the Force)
I have no idea what the bus situation was from RVA (or any other resort for that matter) so I can't say if the Skyliner was better or worse than buses; whole research effort (RVA to HS to RVA) was ~two hours but the rest of my team was asleep and it was a pleasant morning so it was a good excuse for some exercise!
here's a few pictures for you to judge for yourself
line at Caribbean Beach transfer station ~8:15am before anyone was let in (I walked there and back to survey)
View attachment 534740
Hollywood Studios temperature scan, security, and park entry at 9:28am (doable in 30 mins maybe?)
View attachment 534739
line for Hollywood Studios from Caribbean Beach station when I was on my way back to RVA (~9:45am); when I joined the line from RVA on my way to Hollywood Studios, I was under the Skyliner (bottom left of the photo) so it was considerably longer when I passed back through
View attachment 534737
edit: typos