Dear ccc1965:
Regarding lymphedema:
1.). How typical? As you noted, it depends somewhat on the number of lymph nodes removed, a body's reaction, etc . There are many factors. I had 5 lymph nodes removed from the axilla and upper arm, and have lymphedema in my right arm. Everyone is different.
2.) Timeline? Can happen pretty fast. Within 4 days of my mastectomy I started treatment which consisted of using a compression sleeve. Some people get lymphatic massage--helpful to some and not others. However, if you even think you may be developing it, if you even have a hint, ontact your surgeon right away--don't wait. Your surgeon can get you into the correct compression garment which is key to preventing a worse case of lymphedema.
3.) Treatable? It is treatable with compression garments and lymphatic massage, but not presently curable. The leader in lymphedema treatment and research is Dr. Stanley Rockson at Stanford Univ. He has interesting and helpful YouTubes. He is also doing research and has developed a drug to address lymphedema which is still in clinical trials.
4.) Curable? As stated, it is not presently curable.
5.). LDex? I have no info on the L Dex assessment.
Here's wishing you the very best!