To be more clear with making longer samples:
-If you have a really long sample, do all of your adjustments such as normalize, compressor, changing sample rate, etc. first.
-Select the section you want to sample (keep it just under 4 seconds if anything).
-Cut it.
-Open up a new audacity window.
-Paste it.
-Run a Change Speed filter and make the sample twice as fast. This will bring it down to under 2 seconds.
-Save the file.
-Upload the file onto the LSDJ Patcher.
-Save it as a kit or export as a GB ROM.
-Load it up to LSDJ and place the sample kit into the WAV channel.
-Adjust the kit instrument so that the speed will run at 0.5 rate.
-You now have a kit that plays longer than 2 seconds in LSDJ.
Repeat until really long sample is complete.
It is very tedious, but if you really want to use a particular custom kit, you have to put in the mind numbing work. Beer usually helps.