Reduction with deletion

Hi, By saying "reduction with deletion", I mean combining two sentences, which have a common subject, into one sentence by deleting some words, using participles for the second clause and putting comma between two clauses.

After I have seen sentences that use participles at the end of the main clause with a comma to give extra information about the subject of the main clause or something about the main clause, I wanted to learn about this usage because I come across this usage very often in speaking. For example:

1- The funeral is at 3.00, followed by a reception at Shaw's bar. (Original) (Gives more information about the subject of the main clause)

I think this is a combined sentence from two sentences: (The funeral is at 3.00. ) + (The funeral will be followed by a reception at Shaw's bar.)

2- I am psyched to go on this week-long cruise, just sitting around doing nothing. (Original) (He is saying what he is gonna do on this trip)

I think this is a combined sentence from two sentences: (I am psyched to go on this week-long cruise.) + (I will just sit around doing nothing.)

Note: (I have taken this examples above from a tv-series)

3- Essos is an immense landmass located to the east of Westeros, extending into the far east of the known world. (Original) (Gives more information about the subject of the main clause.)

I think this is a combined sentence from two sentences: (Essos is an immense landmass located to the east of Westeros) + (Essos extends into the far east of the known world)

When I am allowed to use this "reduction with deletion" ? Is having the same subject in the main and participle clause enough to combine them into one sentence?