The LX10 would be considered as an "Upgrade" if you are want to shoot macro 4K video because the crop factor would make it about 108mm. For the LX100, the macro 4K video is only around 87mm after crop factor. In term of setup, the LX10 gives you the most bang for the buck because the complete housing, tray and vacuum can be purchased for US$1250.
The LX100 complete setup could be expensive for point and shoot:
- Housing: $1200
- 67mm short port: $180
- Flip diopter (it's the only way you can use macro diopter) $220
- Flexitray II: around $250
- Vacuum valve: $220
If you are new to UW video/photo, I would say the LX10 is a good starting setup and is budget friendly.