This is one of those headphones that may actually warrant going for a higher-power, more robust amp... a separate DAC + HPA stack may be your best bet here.
The DX3 Pro+ makes it to about 1.8 Vrms into 12 ohms. Which is a more than decent ~270 mW, or 111 dB SPL peak with 87 dB/mW, which ought to be quite sufficient. Still, it's clearly very much current-limited at this point, and the thermals would have me slightly worried.
A DX7 Pro+ makes it to 2.4ish Vrms into 12 ohms. Better but a lot more expensive, too.
Let's have a look at some dedicated amps:
JDS Labs Atom Amp+, a little over 3 Vrms.
SMSL HO100, almost 4 Vrms. (IEC Class I device though)
Schiit Magni Heretic, 4 Vrms.
An L30 II can still drive an impressive >6 Vrms into 12 ohms (~3.3 W or so) without a hitch.
Sabaj A10h is almost as unbothered as the L30 II but offers less gain.
SMSL SH-8S, a little short of 6 Vrms, too. (IEC Class I device though)
L50 is basically the same as L30 II, maybe a bit better.
Cheap dac old and range topping mobile phone oleds aren't anything like the same thing, nit even the same sport. That said this looks brilliant.
audiosciencereview.com
Here's the maximum output power vs load of Topping's most powerful headphone Amps:
View attachment 248021
IMHO: Best budget option - L30 II with a matching inexpensive DAC (dongle if need be). Should be sub-$300 all in, possibly even sub-$200. Even substantially more expensive combo DACs won't have that much
oomph.