After L4s you have a bunch of options, heres my take on it, please do note that different people like different things so you’ll get some different opinions, but for me it is something like this:
L4s in sub optimal ships - I like doing this and by far my favorite is Vedmak. Its actually a ton of fun and a good break from flying other ships. I have also done L4s in a Moa and couple other ones that most players shun most of the time. this is purely for my own enjoyment and as proof of concept not to make ISK.
L5s - I gave up on them, I’d have to join a good LS corp and sadly, there just aren’t enough of them left in the game quite literally for me to join. Alternative is to make a literal army of mission pulelr alts and this is not the way I want to or like to play. Its ■■■■■■■ stupid. Not what I consider good or fun gameplay.
Marauders - I regret putting SPs into them. They’re only use is HS L4s and maybe some WH sites. I do not reside in a WH so that is out for me, and for the HS L4s I can do much better and much faster in any meta cruiser or even some of the sub-optimal ones mission / faction depending, and on top of that at fraction of costs and without the clunkiness that comes with battleships. Their only upside is the reduction on MJD cooldown, but they’re just too limiting in the types of content they can do and completely unnecessary for L4s. O and I hate being rooted from bastion.
DED sites - DED sites are actually pretty nice if I get escalations. I fly cloaky Loki or sometimes still Tengu for them and they usually but not always end up in 0.4 systems. Often I bring out my recon alt jsut in case and dual box and its been a really long while since I actually lost a ship doing them, maybe 2 years or so. It is both fun and profitable, however, it does kinda suck when you don’t get escalations from your initial sites. It gets a bit too grindy to the point that I stop and go do something else.
Abyss - I’m kinda over it, but still run it here and there to break the monotony. Its still OK. I very much recommend getting into it and getting to at least the point where you can farm T4s and do some T5s. You don’t have to stick with T5s, they get stressful on me, too much overheat management etc. Also the 20 minute timer is a bit of an issue because when I have a connection problem and get unlucky all 3 rooms with battleships then I eitehr lose a ship or its very close on the timer, so I like to backtrack to T4s for this reason as well, to have more time in case of disconenct. So I scale back to T4s and chill.
Explo stuff, not worth it unless you go daytrip into WHs or elsewhere. Although, I actually have ran into some ghost sites in LS which was pretty nice.
Events - CCP seems to have basically ruined them, from this point onward they will most likely either be super shitty or abandoned. There is some minor hope that they will get it right again, but its highly unlikely.
You can also hunt some clone soldiers in LS belts in a PvP fit T3C. But of course that will draw you in some fights sooner or later, especially if you do it repeatedly in same area, someone will notice. I actually love clone soldiers, every time I do escalation into LS I swing by the belts and fly around looking for them and sometimes I get really lucky and get several in a row. though I don’t do specific clone soldier hunts anymore, haven’t done for a long time.
Epic Arcs - You’ll need a super tanky Battleship if you want to completely solo, I do them in a double prop (MJD, MWD) cruise missle Scorpion Navy Issue. I highly recommend this ship for this purpose. Double Adaptive Invuln, Double prop, cruise is an excellent combination on it because it has 8 mids. Ammo reload is 10 secs and you can switch between precision and high DPS even mid combat as well as different damage types. You can repeat each epic arc once every 3 months. The payout is not that great, but you get a ton of faction standing and its something different to do.