1988 328 GTS intermittent high idle issue

Looking to Ferrari chat for assistance with a random/ intermittent issue with my 1988 Ferrari 328 GTS.

I am a new Ferrari owner since December 2022. Yes, I have no doubt, it will be a learning experience.
Prior to purchasing my Ferrari 328 GTS, I did obtain a thorough PPI from Automotive International- Charlotte. I spoke with Sean Smith numerous times during the PPI about the car- he stated it was a better than average 328, better than many he has evaluated and overall a very solid 328. The PPI highlighted it needed cam belt service, which I well knew needed replacement every 3 (+) years, A/C clutch not engaging. Which I shared with the seller, RK motors- Charlotte, whom told me it was a wiring issue they would repair prior to sale and commensurate with delivery of the vehicle. After purchase, prior to driving more than 10 miles- knowing timing belts needed replacing- I took my car to ***************** MAG for service. The complete cam timing belt service was completed, with me opting to replace the water pump as well * since you're in there* this repair totaled $5482.39- whew..! Service completed, I picked my "new" car on Saturday- Mar 04, 2022, A huge smile lit my face as I was driving home spirited, acceleration- shifting through the gated 5 speed, the sonorous, enticing, intoxicating sound of the 3.2 V-8 encouraging more and more..! 80, 90,120+ mph was exhilarating..! particularly with the targa top off, wind rushing past on 285 W to 75 N. The only thing that dimmed this exciting, exhilarating moment - alarmingly, I notice the accelerator seemed stuck..? while negotiating traffic, I took my foot off the accelerator and noticed the rpm stayed 3500+ rpm several occasions, this I found this extremely concerning.. I blipped the pedal several times thinking the cable was stuck, muck- grease stuck, or possible a mechanical issue ran thru my mind.. A third and fourth time I blipped the throttle and the rev's finally decreased. As I finished my ride home ( @ 28 mi ) the throttle idled high several more times at stop lights- an awful feeling settled in my gut.. mechanical issue on the first meaningful drive of my new Ferrari 328. A mechanical issue after it just came from repair at *****************. I do not recall it idling high prior to the cam belt service, but, to be clear I only drove it gently less than 10 miles knowing to needed service. I contacted merlin the following week and shared the issue after picking it up 3 days prior and scheduled to bring it in again to be diagnosed/ serviced high idle with driving. While in for high idle service, I was notified of a bad A/C system and quoted a new A/C system repair. This was a bit of an unexpected surprise..? I did want my Ferrari to run and function as it should, I authorized repair of the A/C ,as well as, to repair the high idle issue. Notified my car was complete, advised this repair $5508.70 was due- I arrived to pick it up and requested the mechanic that did the work sit with me for a short drive ride along. Toward the end of our brief ride the accelerator stuck again with high idle again after throttle body repair and A/C repair/replacement. He advised me when he got the car, he thought the throttle body linkage was little stiff, he found rust on main pivot, he cleaned it , greased it and reassembled it- ( only $436.00).
I was a bit flummoxed at this point,,!! Way more than a good bit disappointed to again experience high idle after expert repair from *****************. Nonetheless, I just wished to take my car home and hoped perhaps, with additional driving the throttle might self correct..?
So, long story short - my 328 which I am infatuated with when I drive it, it still intermittently idles high on frequent occasion when driving- I would gratefully welcome someone to share similar experience and/or the fix to this issue.. Thank You for your assistance..!!

 

TY for your thots Cenzo. yes, the floor mats are factory, indeed, I did check for mat encroachment.

 

TY Sigma, I have not checked personally the TPS, but, that does seem to make since- I would be curious if merlin checked my TPS..? good input, TY

 

TY- no, they are factory mats. I did check for this mat issue, TY

 

Thank You Steve, appreciate your comment. info: what I have noticed is when I start the car- it idles fine, with a nice low, pleasing Ferrari burble @ 900-1000 rpm'ish. what I have noticed is the high idle issue occurs after driving the car several miles, when the car is hot and seemingly when I am spirited driving 5000-6000+ rpm shifting.. hope this info helpful. I believe the high idle issue seems to occur when the vehicle is hot and when driving- if that makes sense..? TY Steve