https://github.com/platformio/platformio-core/issues/2708

extra_script_libdeps.py

Import("env")

import os

PROJECT_CFG = env.GetProjectConfig()

STORAGE = os.path.join(env["PROJECT_DIR"], PROJECT_CFG.get("common", "shared_libdeps_dir"))
LIB_DEPS = env.GetProjectOption("lib_deps")

#print("using", STORAGE)

def subprocess_libdeps(storage, lib_deps):
    import subprocess
    args = [env.subst("$PYTHONEXE"), "-mplatformio", "lib", "-d", storage, "install"]
    args.extend(lib_deps)

    subprocess.check_call(args)

def library_manager_libdeps(storage, lib_deps):
    from platformio.managers.lib import LibraryManager
    manager = LibraryManager(storage)
    for lib in lib_deps:
        if manager.get_package_dir(*manager.parse_pkg_uri(lib)):
            continue
        manager.install(lib)

library_manager_libdeps(STORAGE, LIB_DEPS)
#subprocess_libdeps(STORAGE, LIB_DEPS)

platformio.ini

[common]
shared_libdeps_dir = my_project_libraries

[env]
platform = espressif32
framework = arduino
lib_deps =
    https://github.com/me-no-dev/AsyncTCP#d1f28ff8
    ArduinoJson@5.13.4
lib_extra_dirs =
    ${common.shared_libdeps_dir}
extra_scripts = pre:extra_script_libdeps.py

[env:a]
board = lolin32
src_build_flags = -DCFG_A

[env:b]
board = lolin_d32_pro
src_build_flags = -DCFG_B

src_main.cpp

#include <Arduino.h>
#include <ArduinoJson.h>
#include <AsyncTCP.h>
void setup() {
    Serial.begin(115200);
    Serial.flush();
    #if defined(CFG_A)
        Serial.println("CFG_A ACTIVE");
    #elif defined(CFG_B)
        Serial.println("CFG_B ACTIVE");
    #endif
}
void loop() {}