A word of caution: doing this mod can damage your Homey…at least I think I did.
After changing out the antennas I monitored the different protocols for a couple of days. The zigbee is hard for me to evaluate since I only have one unit (Aqara multisensor) but the Zwave looked really good after the mod.
However the 433 MHz system didn’t do much better than with the original antenna which was a shame since the main reason for me to do the mod was to get stronger and better 433 MHz communications. To see if there was something wrong with the new 433 MHz antenna I tested two other external antennas that I know are good. No difference…but after testing the last one, a big guy, suddenly the whole 433 MHz system went offline.
After doing a lot of trouble shooting (even placing the original antenna back on the board) and good instructions from Athom support we now have came to the conclusion that the 433 MHz system is indeed dead.
I have no idea what could have caused this…did the big antenna demand too much from the 433 MHz chip? Did I accidentally short something out when soldering the antenna wires? Who knows…my Homey is now functioning great except for 433 MHz and I have to decide what to do. Send it to Athom so they can take a (costly?) look? Buying a new? Buying a used?
I knew this was a risk I took when I put the knife to Homey, so I’m not bitter…I will have a working Homey again…but my biggest problem is to decide if I dare to do the antenna mod again. 
