I’ve checked this with internal that Resizable BAR is EP(GPU) feature not RP(Tegra PCIe)
Linux subsystem has this support. If GPU supports it then should work fine.
You can refer to Specifications | PCI-SIG (pcisig.com) for Resizable BAR Capability.
It seems your RTX A4000 supports this, and you can also refer to the following topic.
A4000 Resizeable Bar support - #2 by MarkusHoHo