There is a recent release of Win4K3Suite which now offers support for the SDRPlay RSP1A for use as a panadapter on the K3, KX3 and KX2. This release also offers a few enhancements in display performance as well as ClubLog spot aging.
Win4K3Suite is the ultimate control program for your K3S, KX3 and KX2 supporting all options as well as the KPA500, KPA1500 and KAT500 on all radios. It supports the P3, and allows the use of the SDRPlay family of RSPs as a panadapter.
Win4K3Suite includes virtual port technology allowing sharing of up to 6 software programs or hardware devices with no conflicts.
You can see some videos on Win4K3Suite here:
https://www.youtube.com/results?search_query=win4k3suite
and some reviews here: http://www.eham.net/reviews/detail/11214
There is also Win4Yaesu Suite for the FT-991 / A. Based on Win4K3Suite, Win4Yaesu offers complete control of your 991 and 991A transceiver and includes support for the SDRPlay RSP panadapters. It provides access to menu items, frequency memories and has built in virtual port technology allowing sharing of the radio with third party software and hardware. The sharing mechanism is extremely robust and you can operate in contest mode for days.
Win4Yaesu also supports HRD LogBook and DM780 replacing the control program with a much more capable and robust front end.
You can see it in operation here:
Win4Yaesu also supports the SDRPlay RSP software defined radios as panadapters with a TR switch as shown here:
For contesters, Win4Yaesu supports N1MM+ completely including interoperability with the N1MM+ spectrum.
You can download a free 30 day trial here:
http://yaesu.va2fsq.com/download-win4yaesu/
Be sure to read the first 10 pages of the manual for trouble free setup. (Hint: disable RTS in your radio)
Many thanks to Win4K3Suite author, Tom for his ongoing enthusiastic support for the SDRplay family and our ever growing community of RSP users.