Good article - it does give us a sense of where we (and by 'we' I mean the Amateur Radio community, not Lime Microsystems) need to work the transmit strip on the LimeSDR or have ample preamplification off-board to drive larger amplifiers. It was my assumption all along that transmit was a side benefit of the LimeSDR - that no one could expect 100kHz to 3.8 GHz at 0dBm to +10dBm. From the LTE response it's apparent that at (about) 3 MHz to 9 MHz the LimeSDR is averaging -40dBm, give or take a few dB. My first inclination would be to review the output circuit on the LimeSDR and determine if it's (easily) tailorable to HF - if not, then study the preamplification, with ALC, that would be necessary off-board to have a constant drive level from 2 - 30 MHz @ +10dBm. Again - all that would be determined by anyone wanting that kind of performance, It's not on LMS to make that happen. Frankly, I'm actually looking forward to researching this and posting on it when I have something solid to offer. But the article does put things into perspective for transmit and does a good job on the recap of the 'EasyFix' for receive, too.
73 de Marty, KN0CK