[Footprint editor] Array tool: No way to use lowercase letters for pin numbers

Description

The "Hard Metric" style of standard backplane connectors has (usually) five rows of through-hole pins, and pins are always numbered starting from a1, then b1, and so on. I have never seen a document where they are labelled with capital letters.

This is shared with other backplane connectors; DIN 41612 connectors usually also use lowercase letters.

But the array tool in KiCad, which should be useful for making footprints for these, does not support this usage; if I try to set the numbering scheme to "alphabet, full 26 characters" or "alphabet, minus IOSQXZ" and tell it to start numbering from 'a' (rather than from 'A'), I get this error message:

The array tool should allow you to use lowercase letters for pin numbers.

KiCad Version

Application: KiCad Footprint Editor x64 on x64

Version: 9.0.7, release build

Libraries:
	wxWidgets 3.2.8
	FreeType 2.13.3
	HarfBuzz 12.2.0
	FontConfig 2.15.0
	libcurl/8.17.0-DEV Schannel zlib/1.3.1

Platform: Windows 10 (build 19045), 64-bit edition, 64 bit, Little endian, wxMSW
OpenGL: NVIDIA Corporation, NVIDIA GeForce GTX 1650/PCIe/SSE2, 4.6.0 NVIDIA 581.29

Build Info:
	Date: Jan  2 2026 01:00:49
	wxWidgets: 3.2.8 (wchar_t,wx containers)
	Boost: 1.89.0
	OCC: 7.9.2
	Curl: 8.17.0-DEV
	ngspice: 45.2
	Compiler: Visual C++ 1944 without C++ ABI
	KICAD_IPC_API=ON

Locale: 
	Lang: en_US
	Enc: UTF-8
	Num: 1,234.5
	Encoded кΩ丈: D0BACEA9E4B888 (sys), D0BACEA9E4B888 (utf8)