Hi, no worries, i try to provide as much info as i can; after all if you're keen you should have the right to know. no worries ya.. i'm good
hmmm... if you're thinking of placing a stage piano, it honestly may not be a good idea for the 3 tier A-Frame due to its weight and also perhaps the style of playing. As you mentioned, the X-Stand is already wobbling for you, any A Frame will be worse; in due time the frame may give way. Though its up for sale, this is still the most honest point i'll try to make.
For me the A-Frame held all my synths; all 61 keys - The Fartar Controller, The Ensoniq EPS and The Korg Wavestation at one time until i sold the Fartar and replaced the top with a board.
What i might suggest is get a height adjustable table from Ikea for the stage piano. Layer the A-Frame or other stands on top of that piano; which is on top of the table. You get leg room and most importantly stability.
Yup.. its my number. Do feel free to call or message. i'll be here.
No i dont perform actually. i'm an audio engineer for audio, film and broadcast. have been at it for like 23yrs - love it to bits however getting old now... anyway i'm also a classical guitarist and synthe and keys are just to facilitate the works.
If you need help on mix and mastering or whatever, just feel free to ask; am happy to help. Cheers!!!