Pairing more than one Link2Cell systems to one cell phone

I had a Panasonic TX-KG885SK Link2Cell system with 6 handsets connected and working very well in my house. I wanted to add one more handset but 6 is the limit on most Panasonic Link2Cell phones.

First I purchased an AT&T Connect to Cell system from a seller in the marketplace. I paired it to my iPhone 6s successfully and the Panasonic unit also remained solidly paired. Ran into a problem though... only one of the systems would allow both receiving and outgoing calls, while the other would only allow outgoing. I could pair the Panasonic first, the AT&T second, and vice-versa but only the first system paired would work for both types of calls. So I gave the AT&T away.

Next I purchased a Panasonic KX-TG9541 2 line, Link2Cell system (singly capable of pairing with 4 different cell phones) and paired it up along with the original Panasonic. This worked but I just didn't like the KX-TG9541 as it has far more complexities and is a bit confusing. I have it for sale at this point.

Finally I added another TX-KG885SK identical to the first. I was able to use handsets from both systems for both incoming and outgoing calls. They both seem to have good volume and clear sound. TADA!!

I'm probably nUtZ for trying this but danged if I didn't have to know. The answer to my original question has to be a qualified yes understanding the Link2Cell and Connect to Cell did not play friendly together, but both Panasonics did. So, it can be done.

ps: I unpaired the iPhone 6s and paired both bases to a single Samsung Galaxy A20. Both systems work fine.