I like the patch easy to read and very informative. Thanks for sharing !

That's really great !

@calp In a procastination wave, I'm rewriting this external withour flext, but with pdlibbuilder.
It should be easier to compile
https://github.com/jyg/smpte-
EDIT : I succeeded in crosscompiling for Windows 64. Check it https://github.com/jyg/smpte-/releases/download/v0.2WIN64/smpte.win64.zip

as a quick and dirty solution, I would suggest to read, in puredata, a wav file containing LTC audio (generated, for example , with Reaper), with tabread4~

EDIT 1. A bit OT, but for Serato / Traktor coding there is an external vinylcontrol~ https://github.com/lodsb/vinylcontrol , and you can also get audio files from serato website https://serato.com/controlcd/downloads
EDIT 2 : found this that may interest you, but you'll have to compile it with FLEXT framework : https://github.com/kronihias/smpte-

@schitz As specified in the pd-dnd-plugin readme file , you have to get tkdnd by cloning or downloading https://github.com/petasis/tkdnd.git
But, even more simpler, there are release files where you can get binary files for every platform, without need to compile : https://github.com/petasis/tkdnd/releases/tag/tkdnd-release-test-v2.9.2

or you can create an abstraction with the name of the patch in a subpatch, by dynamic patching.
This way you can close the patch by sending a [clear( msg to the subpatch.

for example, see [pd $0-sub] and [pd load_subscene] in https://github.com/Ant1r/ofxPof/blob/master/example/pd/pof_main.pd

AFAIK, MobMuPlat is pd vanilla 0.48.1 with no externals.
Don't know about pdparty and pddroidparty,
But there is also POF for android, with an apk somewhere on the web... You can download the desktop version via deken and try it. POF has a .json parser and web parsing features. May be it can fullfill your requirements. As it is based upon Openframeworks and libpd, it would be theoretically possible to add c++ externals. But still a lot of work...

@Dizzy-Dizzy Before saving and closing your patch, you have to send manually a [save $1( message to right inlet of all pp.objects of interest (where $1 is replaced by a "preset"number of your choice).
When you re-open the patch, you have to send a [recall $1( message to the same inlets.

@Mortfell yes you certainly created a list atom (Put menu, List item, or ctrl + 4 in pd 0.52)
something like this :

Yes, listbox is definitively the culprit, and, unlike other not created objects, this one not only isn't recognised, but also doesn't increment the internal pd-object-related indexes, and then the connect messages don't refer anymore to the correct boxes.
Anyway, backwards compatibility means you can execute with 0.52 an older patch (created with an earlier version), but not the opposite (forward compatibility )