I am suffering with pain at the bottom of my left hand thumb joint and think this could be arthritus as it is also in the same place on my left hand but to a lesser degree. Looking for ways to eliviate it if there are any and I will probably try and get to see the doc shortly.
Currently using a Promethean 3110 a nice compact arrangement using the aux input fed by a tablet for track listening. Also used, like kodiakblair, a Hotone Nano but put it through a 4ohm Barefaced 210.
Looking at the backplate of the speaker if you are mounting it on the combo as the photo shows a right angled jack plug may not be the best option as the depth of the plate could cause the cable run to go up then loop down. A straight jack may be better here.
Not a Lakland owner but would point you in the direction of Newtone strings who can wind bespoke gauges for you and also offer options such as steel or nickel, standard or fine outer windings and round or hexagonal cores. You should be able configure almost anything you like (except flat wound).
I have powered a pedalboard tuner plus TC Electronics successfully from a 7800mah powerbank using a 5v to 9v converter cable from MyVolts. Lasted a pretty long time (at least 8+ 45 minute practice sessions before needing to recharge).
You could always try their Platinum range with a hexagonal core. They are physically very smooth feeling with a decently high tension and produce very pleasant fundementals. There is a video demonstrating all the bass string variants on their website.
I have just put a set of the new nickel 46 - 100 Shorties on a bass and they are sounding really good.
The Leathergraft I have has five slats in the ladder Schlippy. I also asked for a specific length between the end keyholes (104cm as I am only short😁) which cost an extra £5.