Pass Labs x250.8 vs tube amps

I have a beautiful system. Lumin X1 > BAT Rex 2 pre > Pass Labs x250.8> Sound Labs M545 (ESL) in a tiny room (9x 11 ft).  This system has the most glorious SQ: smooth, detailed and powerful , along with great bass. I would say this sound equals or betters any ultra high end system. HOWEVER, I have a problem. My system takes 6 hours of music playing to sound this good. I had X250.5 and I had the same issue. Leaving it on idle overnight doesn’t solve the problem. It is 15 W class A, so it generates quite a bit of heat, and yet I have to still play music. Because my room is small, I don’t crank up too much- maybe this is the problem, but the temperature doesn’t complete stabilize for 5-6 hours. The top reaches 107 deg in 2 hours, but the front plate doesn’t reach 107 until the 6 th hr when it starts to sound glorious. I have never had a tube amp and I am wondering if I can reach that thermal equilibrium and the glorious SQ faster with a tube amp? I worried about the heat generation with a tube amp in this small room, but X250.8 generates 450 W just idling. This is no worse than tube amps like Audio Research 150 Se, which I demo’d and was impressed by. BTW, I need power in the amp because of the esl speakers.
What do you all think?

I own a Ref150 SE, it is at its best in 35-40 minutes but I must run an AC unit 12 months a year to be able to stay in the room ! LG 12MBH mini-split with low ambient kit for winter months, use it with Magico V3 ( not the easiest speaker to drive) never used it with ESL though... excellent sounding amp IMO
Why don't you try getting a heat lamp and aiming it at the the heatsinks for 30min before play? That's a $20-$50 experiment that is a lot cheaper than getting a new tube amp.
I have the Metronome Technologie C6 (tube) and the Wavac 805m :they does not give the heat you think. In a half hour he sounds great. After one hour:it’s optimale !
hi, i had great expiriance with  vitus ss-025, it has 25 watts class a , 300 class  ab into 8 ohm and 600 into 4 ohm... after 2 hr. +/-     it sounds like magic- fantastic.  the closest i ever heard ss amp to tube sound...  and when not listning i leave it on mute...
6 hours is surprising to me. I’ve spoken to Kent at Pass. The Mosfets perform to their specs when they reach 50 degrees Celsius. That’s about 125 F. If you leave the switch on on the back I think the unit warms up in a little over an hour. But now you’ve made me curious. I’ll leave it on for 6 to see for myself. Btw, after 3 hours, I can put my hand on the amp and it feels like a warm, not hot cup of tea.